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N A U IA d v a n c e

S c u b aD i v e r



N A U I A d v a n c e d S c u b a D i v e r

T A B L E O F C O N T E N T S

Learning Goals 4

Becoming a Better Diver 4

How to Have More Fun 4

The NAUI Advanced Scuba Diver Course 6

Continuing Your Diving Education 7

How to Use This Text 8

Learning Goals 12

Getting Your Act Together 12

Dive Planning 12

Advance Planning 12

Getting Ready 14

Planning for the Dive 15

Buddymanship 18

Buoyancy Control 20

Closing the Dive 22 Recognizing and Handling Stress in Diving 23

Preparedness and Training 24

Learning Goals 40

Introduction 40

Equipment 41

Procedures and Precautions 44

Overview of a Typical Introductory Dive 46

Learning goals 50

Introduction 50

Possible hazards 50

Equipment 51

Preparation 53

Procedures and Precautions 55 Overview of a Typical Introductory Dive 58

Learning goals 62

Aquatic Life Studies 62

Activities 62

Equipment 62

Procedures 64


Learning goals 70

Introduction 70

General procedures 70

Basic Procedures of Search and Recovery 72

Equipment 72

Techniques and Precautions 73Overview of a Typical Search and

Recovery Introductory Dive 77

Learning Goals 80

Introduction 80

Possible hazards 81

Learning Goals 28

Introduction 28

Equipment 28

Measuring Distances Underwater 30

Natural Navigation 32

Compass Navigation 33

Surface Positioning 36




Throughout this study book there will be sections

that require your special attention. The following icons

are used to mark these sections.

Indicates a warning or safety

information.

Indicates responsible diving practice.

I n d e x 1 0 4

T a b l e o f C o n t e n t s

Equipment 82

Procedures 83

Legal and Ethical Issues of Wreck Diving 84


G e t t i n g t h e m o s t o u t o f t h i s b o o k

Learning Goals 88

Introduction 88

Getting Started 88

Some Fundamentals 89

Equipment 90

Basic Principles 91

Picture Taking Techniques 93Overview of a Typical Introductory Dive 93

Learning Goals 98

Something for Everyone 98

Underwater Hunting 99

Collecting 101

Choices, Choices 103



C H A P T E R

I n t r o d u c t i o n




L E A R N I N G G O A L SIn this chapter you will:

1. Learn what to expect in your Advanced ScubaDiver Course.

2. Learn what your advanced training will prepare

3. Understand the value of continuing your

education.

4. Discover how to best utilize this textbook.

B E C O M I N G A B E T T E R D I V E RWelcome to the NAUI Advanced Scuba Diver Course.

In your entry-level course you gained access to the

underwater world. You acquired a basic knowledge of

this other world and how it affects you. You learned

about the equipment that you use, and you mastered the

skills necessary to manage diving's risks and be a com-

petent, comfortable diver. There was a lot to learn just

to get started, and you have every right to be proud of

being a certified diver.

As you finished the course, your instructor probably

congratulated you and also admonished you with words

of caution such as: "You are now certified to continue

learning how to dive." A newly certified diver is considered

competent to dive without supervision provided the activi-

ties, the diving area, and the diving conditions approxi-

mate those in which the diver was trained. Your instructor

also told you that there were courses available to help you

learn much more about underwater activities and to

become a safer, more experienced diver (figure 1-1).

You have chosen the correct route by seeking train-

ing to increase your qualifications and, thereby, your

opportunities. You will be able to do more, to dive in

areas other than those associated with entry-level train-

ing, and you will have fun as you are accomplishing

these objectives. This is what the NAUI Advanced Scuba

Diver Course is all about.

F I G U R E 1 - 1 . Y O U R N A U I D I V E R C E R T I F I C A T I O N S A R E M O R E

T H A N E V I D E N C E O F A C H I E V E M E N T , T H E Y A R E

" L I C E N S E S T O L E A R N . "

H O W T O H A V E M O R E F U NYou may have discovered by now that diving is not

really an end in itself after the initial learning experience.

Diving is really just a means to allow you to pursue

endeavors in the world beneath the water. You know of

many of them: photography, studying aquatic life and the

environment, exploring, wreck diving, etc (figure 1-2).

Some of these may be appealing to you, and others may

seem far beyond anything you think you'll ever attempt.

The important point, however, is that diving is mostenjoyable when you have a dive objective. You may just

want to explore a new area, learn how fish and other

creatures live, search for a wreck, or seek some trophy;

but you have a motivating reason to dive and can expe-

rience exhilaration when you succeed. This can make

diving even more fun. What you want to do is to discover

an underwater pursuit and become proficient enough in

it to ensure a reasonable degree of success.

you t o do.



C h a p t e r 1 - I n t r o d u c t i o n

sterile one. During your Advanced Scuba Diver Course

you may be introduced to a variety of good diving loca-

tions in your region. These sites will add to your enjoy-

ment for years to come... (figure 1-3).

So, read on and find out more about the Advanced

Scuba Diver course. You will be introduced to night div-

ing, deep diving, underwater navigation, or other local

interests. These introductions plus discovering new dive

F I G U R E 1 - 2 . O B S E R V I N G A Q U A T I C L I F E O R E X P L O R I N G W R E C K S I S

A F A S C I N A T I N G A C T I V I T Y M A D E M O R E E N J O Y A B L E B Y

A D V A N C E D T R A I N I N G .

The first step in selecting an underwater activity

is to determine if any above-water hobbies, such as

photography or bottle collecting, can be adapted to

sub-surface activities. If this is the case, a NAUI specialty

course on the subject can quickly provide the education

to help you successfully adapt your hobby to the diving

environment.

If you are not sure which activities might provide

enjoyment and satisfaction for you, you are in for the

excitement provided by the NAUI Advanced Scuba Diver

and Master Scuba Diver courses. Your instructor will

give you opportunities to experience several of the popu-

lar activities. You can then decide which of them youwould like to further develop by completing the respec-

tive NAUI Specialty courses. The Advanced Scuba Diver

course will also introduce you to more advanced "tools"

of diving such as deeper water diving and underwater

navigation skills.

Another way to have fun is to dive at sites that offer

a variety of things to see and do. You will have more fun

in a diverse, interesting area than you will in a boring,




F IG U R E 1 1 D I V I N G A V A R I E T Y O F S I T E S A N D T R Y I N G N E W D I V I N G A C T I V I T I E S W I L L E X P A N D Y O U R O P P O R T U N I T IE S F O R F U N A S A N

A D V A N C E D D I V E R .

sites are fine ways to have fun, to learn to enjoy diving

even more, and to become a better diver... all at the

same time (figure 1-4).

T H E N A U I A D V A N C E D S C U B A D I V E R C O U R S EIf you are a new diver wanting to gain experience

while increasing your diving abilities, getting oriented to

new dive sites, and having fun, this is the course for you.

If you have recently moved into a new diving area or arecertified through another agency and would like to

obtain a NAUI certification, the NAUI Advanced Scuba

Diver Course is also perfect for you. It is an all-open

water mid-level, continuing education certification

course for divers who have successfully completed a

NAUI Scuba Diver course or have equivalent training

or experience.

The course consists of at least six open water dives.

You will review basic skills, learn much more about the

environment, navigation, dive planning, and dive safety.

The course is likely to include an orientation to some of

the following subjects:

1. Navigation

2. Night or Low Visibility Diving

3. Deeper Diving

4. Search and Recovery

5. Boat Diving

6. Light Salvage

7. Hunting and Collecting8. Exploration and Underwater Mapping

9. Non-Penetration Wreck Diving

10. Research Diving

11. Fresh Water or Ocean Diving Orientation

Upon successful completion of the course, you will

be certified as a NAUI Advanced Scuba Diver and will be

considered competent to plan dives and to accomplish

underwater tasks similar to those contained in the



C h a p t e r 1 - I n t r o d u c t i o n

F I G U R E 1 3 . N A U I A D V A N C E D S C U B A D I V E R T R A I N I N G W I L L

I N T R O D U C E Y O U T O A V A R I E T Y O F F U N D I V I N G

A C T I V I T I E S .

course. You will also be qualified to enroll in the NAUI

Master Scuba Diver course and in all NAUI Specialty

Diver courses...

While you will receive an introduction to some of

the specialty areas of diving, you will not receive enough

training to be considered proficient in them. But you

will have a good idea of the interests you would like to

pursue and be qualified to participate in NAUI Specialty

Diver courses (figure 1-5).

C O N T I N U I N G Y O U R D I V I N G E D U C A T I O NAfter your NAUI Advanced Scuba Diver Course, you

may wish to take a NAUI Master Scuba Diver Course to

further expand your capabilities and to develop more

detailed general diving knowledge and further experi-

ence diving specialties. After your Advanced Diver Course

or Master Scuba Diver training, you should have a good

idea of one or more underwater activities in which you




F I G U R E 1 5 . A N A D V A N C E D S C U B A D I V E R C E R T I F I C A T I O N C A R D N O T O N L Y S H O W S Y O U R A D D I T I O N A L E X P E R T I S E B U T M E E T S P R E R E Q U I S I T E S F O R

M A S T E R S C U B A D I V E R A N D O T H E R C O U R S E S .

would like to engage. There are only two ways to become

proficient in a specialty area: you can learn through

trial and error-the experience method-or you can be

taught by someone who has the expertise to help you

avoid errors and get desired results right away. While

experience is said to be a good teacher, it usually gives

the test before the lesson. That is why we recommend

learning from a NAUI instructor. Pick out the specialty

you want, then enroll in a NAUI course for that particu-

lar interest. You'll quickly learn the correct procedures

and will soon be achieving your desired goals.

The aim of NAUI is to educate people to have fun

while diving as safely as possible. After you learn the

basics, you gain experience under supervision. Later you

increase your knowledge and skills while being intro-

duced to special interest areas. You will develop profi-

ciency in the specialty, and finally pursue your interest

or interests confidently and enjoyably.

H O W T O U S E T H I S T E X TThis book is designed to serve as resource informa-

tion for the NAUI Advanced Scuba Diver Course. Each of

the chapters provides information on popular diving

topics that may be introduced in your course. Your NAU

Instructor may assign various chapters for you to study,

according to the schedule arranged for your course. The

Table of Contents and the index can help you locate

information on a specific topic. Whether or not all of the

topics in the book are included in your course, you maywant to read about and familiarize yourself with them.

This text will also serve as a fine diving reference book

for your library.



C H A P T E R

C o n t i n u a l

I m p r o v e m e n t





1. Learn the benefit of continual improvement of your diving skills.

2. Review the processes of advance and immediate

pre-dive planning.

3. Be introduced to a who, what, when, where, and

how method of planning a dive.

4. Review S.E.A.B.A.G. and its use as a memory device

for pre-dive equipment checks.

5. Review the buddy system and its benefits to div-

ing enjoyment and safety.

6. Review buoyancy control techniques and meth-

ods for fine tuning buoyancy and ballast.

7. Learn about stress and stress management and

the role that fitness, training and preparation

have on diving safety.

G E T T I N G Y O U R A C T T O G E T H E RYou may be entering the Advanced Scuba Diver

course directly from your entry-level training, or you

may have had some additional diving experience.Perhaps you are here to refresh your skills after a long

period of not diving. In the course you will be expanding

your horizons with a series of at least six dives that

introduce you to a variety of diving activities.

Just as importantly, with each dive you will be improv-

ing your general diving skills, increasing your ability to

plan and execute safe and enjoyable dives, and further

acquainting yourself not only with specialized equipment

but also with your general diving gear. As you advance your

diving skills, you will be taking more and more responsibil-

ity for your own dives. So, before we begin specific diving

activities of this course, let's look at the more general skills

of scuba diving - planning, techniques, and safe diving.

D I V E P L A N N I N GPlanning for safe, enjoyable dives demands care

and attention to detail. There are two parts to this exer-

cise, advance preparatory planning and planning for the

dive itself.

A d v a n c e p l a n n i n gAdvance or long-term dive planning begins

when you decide to make the dive. It may be as simple

as you and your buddy deciding what you want to do

on a weekend day, or it may be booking a week-long

diving vacation to an exotic remote destination.

Preparing for your diving should start immediately.

Begin by listing the who, what, when, where, and how

of your dive.

Who will be your buddy? The decision may be a

matter of course, but with whom you will dive is an

important decision. A good buddy can make the differ-

ence between having fun and not having fun. The prop-

er buddy can mean achieving your dive objective. A

buddy does not have to have the same skill level as you,

but it should be adequate to the planned dives. Your

buddy should be someone compatible and trustworthy.

Your objectives should be similar.

What will you need? Check your diving equipment.

Can you locate everything? Don't wait until the last

minute. Make a checklist. Do you need to acquire someadditional or special equipment? Is your equipment in

good condition? Does it need repairs or annual preven-

tive maintenance? Repairs will take time, so you must

plan ahead.

When are you diving? What water conditions should

you prepare for? Water temperatures and dive-conditions

vary with the season. A location that requires only a

shorty wetsuit in the summer may need a full 6.5-mm

suit in the early spring. Are rough seas a possibility? You

are more likely to encounter adverse conditions in the

winter. If you are susceptible to seasickness, be prepared.

Be prepared to not dive if conditions are bad.

Commercial dive boats will not operate if the seas are

too high or conditions are adverse. Shore divers must be

especially wary of winter conditions when waves and surf

are more likely to prevent diving (figure 2-1).

The time of day can make a difference as well.

Easier diving in calmer water is more likely in the

morning before winds increase and cause chop. If you



C h a p t e r 2 - C o n t i n u a l I m p r o v e m e n t

F I G U R E 2 - 1 . C H E C K C O N D I T I O N S C A R E F U L L Y B E F O R E M A K I N G T H E D E C I S I O N T O D I V E . I T M A Y B E W I S E R T O W A I T F O R A N O T H E R D A Y .

are ocean diving, your choice of dive time may be affect-

ed by the tide. A beach that is an easy entry point at high

tide may be dangerously rocky or slippery at low tide.

Tidal currents are influenced by the state of the tide.

Visibility will be better at high tide when clean water is

coming towards shore. Low tide usually means lower

visibility especially near the mouth of a harbor or other

geographic restriction that produces tidal flow. The times

of high and low tide change from day to day with the

phases of the moon. Consult local tide tables to help

find optimal conditions.

Where are you diving? If you will be traveling

abroad, do you have a valid passport? Without one, your

be allowed to board the plane. Do you need some special

clothing? Should you take an extra supply of any

required medications? Thinking ahead avoids problems

later. Wherever you are diving, you need to be aware of

local regulations. For example, in many places shore

access for diving is permitted only at certain times of the

day, especially in the summer when the beaches are

crowded with swimmers and parking is scarce. Is taking

game, such as lobsters, permitted and are licenses neces-

sary? You need to know and comply with relevant laws

and ordinances.

Another general consideration is departure time. If

you are traveling to your destination by air or if you are

diving from a commercial dive boat, knowing the depar-

ture time is important. Be sure that you allow enough

time to arrive well ahead of scheduled departure. This

will also provide some contingency time in case you are

delayed by traffic or a minor mishap on the way. Your

flight will not wait for you (unless it is your private air-

plane), and the captain of a dive boat has commitments

to the other divers on board and is not likely to delay

sailing because you are late.How are you diving? Will your diving platform be

the shore or a boat (figure 2-2)? Organize your plan for

getting there. Can you car-pool? Where will you park? If

you are boat diving, remember that everything you need

has to go on board with you. Some of the other things

you must consider about where you dive have already

been discussed. If you are diving with a group, some

decisions, such as choice of dive site and appropriate

dive will end at the airport check-in because you won't




conditions, may be group decisions or will be made by

the boat captain, divemaster, or group leader. But

remember that their decision to dive does not removefrom you the responsibility to not dive if you do not feel

comfortable with the diving choices and the skills and

ability required of you.

G e t t i n g R e a d yFinal preparations will go more smoothly if you

allow enough time to accomplish them easily. Don't

wait until the last minute to pack. If you have to rush,

you are more likely to forget some essential item. Make

your personal checklist. It often helps to pack the nightbefore your departure and "sleep on it." You may wake

up remembering something you left out.

If you are packing for the dive itself, pack your gear

in the dive bag in the reverse order that you will use or

assemble it. This will make your dive preparation at the

site more organized, and you will not have to spread

your gear all over the boat. Protect any equipment that

is liable to breakage by padding around it or putting it

into a hard case. If you are packing for an airplane trip,

protect any instruments that are sensitive to pressure

changes. If they are liable to be placed in an unpressur-ized luggage compartment, either carry them with you

or place them in an airtight container. If you have a

dive computer, read the manufacturer's instructions

about safe transport. Most dive computers will be turned

off and unaffected by pressure changes.

Don't forget to take those extra important items,

such as food, drinks, dry clothes, windproof jackets, hats

sunscreen, and basic first aid supplies. Even if your dive

bag has a dry section, it is a good idea to pack the items

that must stay dry in a separate bag or daypack. These

will not be on your dive equipment checklist, and they

therefore tend to be forgotten. You may want to develop

an accessories checklist to help you remember every-

thing.

Check the weather (figure 2-3). In the United States,

the National Weather Service maintains a web site and

broadcasts 24 hours a day on dedicated radio frequen-

cies. Many other agencies and companies offer global

weather information on the Internet. In many areas,

F I G U R E 2 - 2 . H O W Y O U G E T T O Y O U R D I V I N G L O C A T I O N M A K E S A D I F F E R E N C E I N T H E P L A N N I N G P R O C E S S .




F I G U R E 2 - 3 . A N Y D I V E S I T E C A N C H A N G E R A D I C A L L Y F R O M D A Y T O D A Y A N D S O M E T I M E S F R O M H O U R T O H O U R .

surf conditions will also be posted. You can telephone

harbors, dive boats and fishing boats, lifeguard services,

even waterfront business establishments for current con-

ditions. If you are diving with a charter dive boat com-

pany, call them if the conditions are at all questionable.

The call can save you a lot of frustration if they have

canceled the trip.

Make certain that you and your dive buddy are

physically and mentally prepared for the dive. If either of

you is not feeling well, consider not diving. There is

always another day to dive. Know how you would con-

tact emergency services in the event of an accident.

P l a n n i n g f o r t h e D i v eWhen you arrive at the destination, there are still

many tasks to perform before you actually dive.Evaluate the conditions when you arrive at the dive

site. Ask yourself whether it is safe and prudent to dive. If

you have any doubts, seek an alternate site-one that is

out of the wind, has negligible current, offers easy entry

and exit, has low waves and surf, or whatever will

improve the conditions that make you hesitant about

diving at your first selected site. If you cannot find

acceptable conditions, do not dive. Now that you can see

the dive site, ask yourself whether the dive is within the

skill level of yourself and your buddy. If the dive requires

greater strength or stamina than either of you possess, or

if either of you is apprehensive about the dive, find an

alternate location or cancel the dive.

If you are diving from the shore, choose a good

vantage point from which you can observe entries and

exits as well as water conditions. Determine the size and

duration of wave sets. Look for currents. You can watch

for drift of swimmers or floating objects to determine

longshore currents. Rip currents often show as foam,

areas of dirty water, or disturbances in wave patterns.

Choose your entry and exit points. Have at least one

additional exit site in case some situation, such as a

change in wind, current, or tide height eliminates your

first choice.

If you are on a chartered dive boat, the captain willmake the decisions about the dive location based on

your safety and his or her knowledge of the dive location

and the conditions. You will be briefed about what to

expect - the depth, the terrain, any current or hazards

and what you can expect to see. Remember, the decision

to dive is still your responsibility. The captain can make

you aware of many factors, but you must be the judge of

your own abilities and your preparedness. As with shore




diving, take note of currents, visibility, waves and swell,

and chop and plan your dive accordingly.

If you are diving from an anchored boat, you will

normally descend on the anchor line. Pause with yourbuddy at the bottom of the anchor line to organize your-

selves before proceeding with the dive. Begin your dive

into any current so that you can return to the boat with

the current in your favor. The boat will deploy a trail

line off the stern in case you surface down current. If

you are drift diving or live-boat diving, you will dive

with the current, and the boat will follow. In drift diving,

it is important that the group stay together and surface

together, not scatter all over the bottom.

The Dive Plan is an essential part of every dive.Once you have decided to make the dive, you and your

dive partner need to plan the details together. You should

establish the depth for the dive and its duration. You

should also agree on your air management plan. The

maximum depth of the site may determine the depth of

your dive. Your dive objective, your training, or your

comfort level may be the determining factors if you are

diving on a wall or a drop-off. The planned duration of

the dive will be limited by the time allowed by your dive

tables. It could also be determined by the cylinder size

and your knowledge of your air consumption rate.

You must also take your available air into account.

With good air planning, you will be able to return to your

exit point underwater without a long surface swim. The

turnaround point should be based on the diver with the

higher air consumption. Remember that most dives are

round trips, and you will exit at or near where you entered

the water. There are no air fill stations underwater for the

recreational diver. Turn the dive while you still have

enough air remaining for your swim back. For simple

dives, many divers will begin their return when half of their available air remains (allowing an appropriate

amount for reserve air). A safer procedure is one which is

used in advanced dive situations. Called the "rule of

thirds," the divers turn the dive after one-third of the avail-

able air is used. This allows one-third for return and one-

third for contingencies. Technical divers engage in elabo-

rate gas management plans in which their gas consump-

tion at every stage of the dive is factored into the dive plan.

The three parts of depth, time, and air are the foun-

dation of any dive plan. There are other factors, too, that

have already been discussed, such as method of entry,

planning for the safest utilization of currents, and con-

tingency exit points. Compass bearings and the general

pattern of the dive should also be decided together.

When you have agreed on your dive plan, assemble

and don your equipment and conduct a thorough buddy

check (figure 2-4). Pace yourselves as you assemble your

equipment and don your thermal protection so that you

do it in tandem. If you rush to get ready, you may be

standing in your wetsuit in the hot sun for an extended

period, waiting for your buddy to finish getting ready.

The buddy check is an essential part of every dive.Whether you are diving with a new dive partner or an

old friend, a thorough pre-dive check is fundamental to

a safe dive. The buddy check has several purposes. It

familiarizes each of you with the other's equipment and

its configuration. Either of you should be able to assist

the other with equipment problems if needed. It is an

opportunity to double-check that your own, as well as

your buddy's equipment, is operational before entering

the water. It lets you discuss contingencies such as han-

dling an out-of-air situation while you are looking at

your equipment.

You may have learned a mnemonic, such as

SEABAG, in your entry level course to help you remem-

ber the steps of dive planning and equipment checks.

SEA refers to dive planning and stands for site survey,

emergency plans, and activity. BAG refers to the points of

a buddy check and refers to buoyancy system, air, and

gear. Another way to perform a buddy check is to begin

at your heads and together match each piece of equip-

ment as you work your way towards your feet. Whatever

you use to remember the process, you will check severalspecific points in order to be sure everything is present

and operational.

Buoyancy Compensator:

1. Compare the operation of your BC inflation sys-

tems. Determine how would you add air, both

orally and using the low-pressure inflator. Push

the inflator button on your buddy's BC to make

sure you know how to operate it.



F I G U R E 2 - 4 . I T R E Q U I R E S A C E R T A I N D I S C I P L I N E T O A L W A Y S D O A P R E - D I V E E Q U I P M E N T C H E C K .

2. Familiarize yourself with the closures and releas-

es of the BC. Look for a cummerbund, waist belt,

chest clip, and shoulder releases. Some diversattach their gauge consoles to the opposite side of

the front of their BC. Look for this. It will be one

more release you must make if you have to help

with equipment removal.

Air Supply:

1. Check the existing pressure in your cylinders.

Make sure the air is turned on. Discuss your

turnaround pressure and your back-at-surface

pressure while considering your actual cylinder

contents.

2. You and your buddy should breathe from your

regulators to verify that they are properly func-

tioning. Watch your S.P.G. as you take breaths

and see if the indicator needle is stable. If it

rotates or indicates lower cylinder pressure with

each breath you take it may mean that your tank

valve has been closed or is only partially open

and is interfering with the flow of air. Open it

fully and check it again.

3. Locate your buddy's alternate air source or con-

tingency scuba. How does it operate? Discuss how

you would use it in an out-of-air situation. If youneeded air, would you breathe from your buddy's

secondary scuba or would you use the primary

second stage? Is your buddy planning to hand

over a contingency scuba unit in the event you

need an air supply?

Weighting System:

Familiarize yourself with your buddy's ballast sys-

tem. Is it integrated into the BC, and if so how does the

release operate? Is it a weight belt? Examine the release.

Many types of weight belt release systems are available.

You should not assume that you will always find a

"standard" lever buckle.

Final Check:

1. Look for any twisted, trapped, or entangled hoses

and free them. Make sure all releases are accessi-

ble.

2. Check the operation of all lights if you are night

diving. Make sure that any other special gear is

functional.





F I G U R E 2 - 5 . E V E R Y B U D D Y N E E D S S O M E B O D Y T H E Y C A N L E A N O N .

3. Step back and ascertain that everything looks

right. This may be the point at which you discov-

er a loose tank strap.

Once the buddy check has been completed, you can

proceed to the water. Inform the divemaster or other

responsible person that you are entering the water and,

if appropriate, inform him or her of your dive plans.

B u d d y m a n s h i pThe buddy system increases the fun of diving. The

buddy is an extra set of eyes and hands that can provide

assistance, if needed (figure 2-5). A thorough pre-dive

buddy check as well as a conscientious and observant

buddy during the dive can help prevent a mishap or an

accident. Nevertheless, a buddy team is no place for a

dependent relationship. In that event, only one of the

team members has someone who can provide assistance.

The other might as well be diving alone.

Each member of the team should be a self-reliant

buddy. He or she should be capable of diving safely and

conducting the planned dive. As a team member, you

should feel confident in your own ability to engage inthe dive activity, and so should your buddy. In buddy

diving, you are accepting the responsibility of trying to

assure a safe and comfortable dive for you both. Your

buddy is doing the same. You are not giving up respon-

sibility for your own actions and safety.

A large part of being a good buddy is a matter of

courtesy. You should behave towards your buddy as you

would want them to behave towards you. For the buddy

system to work, both divers must be committed to its

principles. There are several techniques that will help

you perform as a team.

As we have already discussed, you should plan the

dive together, agree on its parameters and objectives,

and conduct a thorough pre-dive buddy check. During

the dive, follow your plan. The optimal buddy team

position is shoulder-to-shoulder, and you should main-

tain the same position relative to one another. You

should consistently be able to glance to one side and see

your buddy. If you fall behind or drift above your buddy,

it can cause an anxious moment when you turn up

"missing." If you want to change position, signal your

buddy of your intentions.

Decide who will be the nominal leader for the dive.

If you will want to change leader, decide on a predeter-

mined signal during your dive planning. The leader has

the responsibility to not out-swim the other team mem-

ber and to allow time for any activities, such as photog-

raphy or fish watching. The other team member should

remember to keep up and get the leader's attention and

signal before stopping. Communicate with one another

frequently and especially prior to changing direction orhalting progress.

Threesome teams should be avoided if at all possi-

ble. It requires an exceptional team member to keep

track of two divers. It is also common to become com-

placent about one's responsibility to the others and inat-

tentive to the whole team. One diver is likely to be for-

gotten. Too often a threesome finishes the dive as a two-

some and a missing, solo diver. Maintaining position




relative to your buddies is even more important and that

much more difficult in a three-member team.

Follow your dive plan. It is unwise to significantly

alter the plan in the midst of the dive. Changing the dive

changes all of the parameters you and your buddy had

so carefully agreed to. Communicating the change

underwater is difficult and usually incomplete or impos-

sible.

As you dive think ahead. Your dive planning will

have covered many contingencies, but remain observant

during the dive. Potential problems can be avoided if

you and your buddy stay aware and look ahead. Avoid

areas that could cause problems. Examine channels andswim-throughs before entering. Remain aware for signs

of current change. Keep your fins high as you enter silt-

ed areas. Pay attention to your navigation.

Any diver should feel free to end the dive at any

time and for any reason. It could be because you are low

on air, or it could be because something just does not

feel right. The signal to end a dive should never be ques-

tioned. You can discuss the situation in your post-dive

debriefing. If the dive is called early, return to your exit

point and make a normal exit if possible, including your

safety stop.

What you do in the event of separation from your

buddy, should have been discussed as part of your pre-

dive planning. In relatively clear water, the usual lost

buddy procedure is to look around from side-to-side

and in a complete circle, remembering to look above

as well as on the bottom (figure 2-6). Ascend several feet

and look in a circle again, watching for your buddy's

bubbles. If you do not locate your buddy within one

minute at the most, begin a normal ascent to the sur-

face, continuing to turn in a circle as you look around,below, and above. Your buddy should be using the same

procedure, and you should surface within a short dis-

tance of one another. If your buddy is not at the surface,

inflate your BC fully to raise yourself higher in the water

and look for his or her bubbles breaking the surface.

Swim over to the bubbles and wait a minute or so for

your buddy to surface. If necessary, follow the bubbles

downward to rejoin your buddy.

F I G U R E 2 - 6 . L O O K I N A L L D I R E C T I O N S T O L O C A T E A L O S T B U D D Y .




B u o y a n c y C o n t r o lFinely tuned buoyancy control is the mark of a

skilled diver (figure 2-7). Comfortable, enjoyable diving

is directly related to the ability to achieve neutral, posi-

tive, or negative buoyancy easily. If you are over-weight-

ed, it is hard to keep your head above water at the surface

or to control your descents and ascents. To counterbal-

ance the excess weight, you will have to add greater

amounts of air to your BC underwater. You will not be

able to streamline your movement through the water

because your weighted waist and buoyant BC will posi-

tion your body at an angle. You will expend much more

energy than necessary just moving through the water. On

the other hand, if you do not have enough weight, it is aconstant struggle to get beneath the surface and stay at

depth.

Individual buoyancy is affected by many factors,

both personal and equipment related. Muscle and bone

mass, wetsuit or dry suit buoyancy, cylinder material

and size, neoprene padding on weight belts, backpacks

and cummerbunds, all affect your buoyancy. Moreover,

the air cells in neoprene wetsuits compress due to

increasing pressure as you descend, and you must com-

pensate for this loss of volume by adding air to your BC.

During ascent, as your wetsuit and the air in your BC re-

expand, you will have to vent this air from your BC.

If you are properly weighted, you will be able to

achieve neutral buoyancy at depth with a minimal

amount of air in your BC, and you will be able to easily

maintain a horizontal position as you swim. You will

expend less energy, have greater control, and be able to

avoid stirring up silt (figure 2-8).

If your buoyancy is adjusted properly, you can use

the amount of air in your lungs to fine-tune your buoy-

ancy. Whether you breathe with your lungs fuller oremptier can make a difference of as much as 3 kg (7

pounds) in buoyancy, depending on lung volume. With

practice, very slight adjustments of your kick, will con-

trol your trim as you breathe and swim underwater. You

will be able to control your vertical motion in the water

with breathing control. Deeper breaths will slow your

descent or actually allow you to rise in the water col-

umn. Longer exhalations will reduce your lung volume

F I G U R E 2 - 7 . F I N E T U N E D B U O Y A N C Y C O N T R O L I S T H E M A R K O F A

S K I L L E D D I V E R .

and allow you to descend without effort.

Remember to perform a buoyancy check whenever

you change your equipment or exposure suit configura-

tion. A surface buoyancy check is an approximation.

After setting your weighting with a buoyancy check, you

may still need to make minor adjustments to your

weighting to dive comfortably.

The guiding principle in weight adjustment is to




F I G U R E 2 - 3 . M A I N T A I N I N G N E U T R A L B U O Y A N C Y A N D T R I M I M P R O V E S D I V I N G E F F I C I E N C Y .

use the minimum amount of weight that will enable

you to be neutrally buoyant with an empty BC during

your safety stop at 5 meters (15 feet). As you end the

dive, the air in your cylinder is depleted, and the cylinder

will be significantly more buoyant. The criteria for a

surface buoyancy check is that you should float at eye

level with all of your equipment in place, your BC empty,

and your lungs full. This is reasonably accurate for a

fully wet-suited diver (wetsuit compression at 5 meters

offsets the increased cylinder buoyancy at the end of the

dive). But if you are dressed only in a diveskin, a stan-

dard surface buoyancy check may leave you a few

pounds buoyant at the end of the dive. Take time on

your next dive to check your buoyancy during your safe-ty stop and make adjustments. Enter your proper

weighting for your equipment configuration in your log

book.

You know that the removal of weight is required

when an ocean diver wants to dive in fresh water, and

that a fresh water diver needs more weight for ocean div-

ing. You can use a rule of thumb estimate how much

weight to add or to remove when the same equipment is

being used. Here's how.

Ocean water is two-and-a-half percent heavier than

fresh water, so it provides two-and-a-half percent more

buoyancy than fresh water. When moving from fresh

water diving to the ocean or vice versa, you must add or

subtract enough ballast weight to change your density

by two-and-a-half percent. In other words, you should

add or subtract about one-half kilogram for every 20

kilograms that you and your equipment weigh (about

one pound of weight for every 40 pounds).

Since most of us have not weighed ourselves with

all of our dive gear, a good place to begin is to add or

subtract one-half kg (one pound) for every 20 kg (40

pounds) of body weight, plus one-half kg (one pound)for the weight of your equipment. Round to the closest

half kg (pound).

Using this rule of thumb, if you weigh 52 kg (115

pounds), you would add 2 kg (4 pounds) to your ballast

weight when you move from fresh water diving to ocean

diving. If you weigh 93 kg (205 pounds), you would

remove 3 kg (6 pounds) when transferring from the

ocean to a lake.




You have completed the dive successfully and had a

great time. When you exit the water, it is time to disas-

semble your equipment, relax, debrief one another, and

enter the dive in your logbooks.

Depending on circumstances you may put your

equipment away, or you may set it up for the next dive.

Keep it out of the way of other divers if you are boat diving

and out of the sand and dirt if you are beach diving.

Rinsing your equipment may have to wait, but you should

keep your equipment as clean as possible. If you are disas-

sembling your equipment, don't forget to drain the extra

water from your BC and to dry and replace the protective

cap on your regulator first stage. On a boat, keep your areaclear and stow your equipment (figure 2-9).

Avoid heavy exercise immediately after the dive. If

you are cold, change into dry clothes and warm yourself.

Drink plenty of nonalcoholic, no-caffeine drinks to

hydrate yourself.

Debrief with your buddy. Talk about the dive.

Discuss what went well and what you could do better

next time. Talk about your objective. Did you accom-

plish it? If so, what helped you do this; and if not, what

can you do differently next time. Exchange your obser-

vations on how well you functioned as a buddy team,

and decide how you want to change your buddymanship

next dive. How was your buoyancy? What did each of

you see in the others who were also diving that could be

made better. Debriefing with your buddy after your dive

is a required activity to become a better diver.

After you have discussed the dive, record it in your

logbook. The debriefing will help you focus on impor-

tant aspects of the dive that you may want to enter,

either to recall memories later or for future reference.

Your logbook provides the place where you can recordany diving information you may need in the future. Use

it to enter information on dive sites and their location,

your air consumption using different cylinder sizes, the

amount of weight you wear with different exposure suits,

the success of various equipment configurations and so

on. Entering water temperature may be useful to decide

how much thermal protection you will want on a future

dive. Your logbook also provides a reference when a

F I G U R E 2 - 9 . A F T E R Y O U R I N S E Y O U R R E G U L A T O R A N D D R A I N

Y O U R B C I N B E T W E E N D I V E S , S T O W I T O U T O F T H E

W A Y W H E N Y O U ' R E O N A B O A T . E V E N O N L A R G E

V E S S E L S D E C K S P A C E I S L I M I T E D .

C l o s i n g t h e d i v e




future trip takes you to a location with a dive operator

who wants to know your diving experience.

R E C O G N I Z I N G A N D H A N D L I N GS T R E S S I N D I V I N G

As you expand your diving horizons, you are more

likely to encounter dives or environments that can cause

excess stress in you or your buddy. Advance planning for

your dive can do much to prevent or control stress so

that it doesn't become excessive and harmful. Deciding

to be aware and observant as you dive can help you

avoid getting into a stressful, uncomfortable situation.Canceling a dive that you believe may be too demanding

should always be an option.

Life is stressful. As we say in the NAUI Scuba

Rescue Diver textbook, "A ship underway in under stress.

A ship run aground is in distress." Excessive stress occurs

anytime there is an imbalance between the demands

placed on you and your ability to respond. It is not nec-

essarily always bad. It should evoke an effort on your

part to maintain or restore your sense of control and

equilibrium. If handled positively, a person will respond

to a stressful situation by concentrating on the cause,

looking for a solution, and acting to remove the cause of

the stress or solve the problem. A positive outcome can

give a feeling of pleasure, exhilaration and achievement.

On the other hand, ignoring stress or denying its

presence can have just the opposite effect. The stressor

can lead to anxiety-fear or apprehension experienced in

the face of a real or imagined danger. The anxiety can

be followed by distraction as more and more concentra-

tion is placed on the anxiety rather than finding a solu-

tion. The anxious person is impaired in their ability tofunction, and very little extra is required to push them

over into a state of distress and panic-a total loss of

control.

As a diver you should know how to recognize signs

of excessive stress in yourself and in your buddy and be

prepared to act to avoid, reduce, or alleviate it. Most of

us recognize stress in ourselves. In diving, you must

learn not only to recognize stress, but also to admit to it.

F I G U R E 2 - 1 0 . T H O R O U G H P L A N N I N G A N D R E H E A R S A L C A N

S I G N I F I C A N T L Y R E D U C E S T R E S S .

Denying feelings of stress is an invitation to a steadily

worsening situation.

Recognizing excessive stress in your buddy requires

observation. Just as you may be reluctant to admit to

your own stress, others may try to deny and hide it. To

develop your ability to avoid the negatives of excessive

stress, you must practice being observant of your buddy's

behavior as well as your own.

When getting ready for the dive, stay aware for such

behaviors as stalling, nervousness, repeated errors,

apparent inability to assemble equipment, withdrawal,or excess talking and humor. As you enter the water,

reluctance to descend, ear-squeeze problems, or difficulty

controlling descent may be signs of excessive stress.

During the dive, one of the surest signs of excessive stress

is a change in breathing pattern from smooth, even

breathing to rapid, over-breathing. Watch for inability to

control buoyancy, jerky movements, or fixation on

equipment, especially gauges. A person experiencing




excessive stress begins to exclude normal awareness as

they turn inward on their own anxiety.

If you feel stress or see signs of it in your buddy, act

immediately to allay the problem. Think in terms of

solutions, formulate a plan of action, and act upon it to

minimize or eliminate the problem.

Before the dive, you have the option of not diving.

You can also talk about the dive, try to determine the rea-

son for the stress and change the dive plan. Sometimes

rehearsing the dive in greater detail will open possible

solutions to the perceived stress. People are more likely to

panic when they run out of options (figure 2-10).

During the dive, it is especially important to act

promptly, but not hastily, to face the problem and find a

solution. Stop, breathe, think, then act is what you

learned in your entry-level class. Apply it now. Stop your

activity and breathe deeply. If you see signs of stress in

your buddy, get them to do the same. When you get your

breathing under control, go to the next step, think about

the problem and solve it. Try to get control of yourself

underwater; don't head immediately to the surface.

Underwater you have plenty of air. At the surface, you

will be subjecting yourself to additional problems of

flotation, waves, breathing, etc. If you can solve the

problem, you may decide to continue the dive. If the

problem persists, such as you are cold or you simply

can't feel comfortable, it is time to end the dive. If you

and your buddy have things under control, you can end

the dive safely. If you react hastily, you may only cause

further complications.

Most of your diving will be enjoyable and not stress-

ful, especially if responsibly planned. Still, it is possible

to venture deeper than you feel comfortable or to get

into a task-loading situation, and realize it only after

you are there. As a responsible and safe diver you should

dive aware, be watchful for stress and take steps to con-

trol it. If the stress is a result of your being inadequate to

the demands of the dive, then return to dives that are

within your ability and comfort level. Seek out addition-

al training to prepare you for more complex and

demanding dives.

P R E P A R E D N E S S A N D T R A I N I N GAny activity requires preparation. Engaging in a

new activity may mean that instruction or training isadvisable. This is especially the case in scuba diving. It

may be possible to learn some advanced diving skills by

reading and private practice or by trial-and-error, but

this is not the safe way to proceed. While it is true that

experience is a good teacher, it frequently gives you the

test before the lesson. One of the reasons you are in this

course is because it offers opportunity to advance your

skills under supervision. As a responsible diver, you

should take the time to prepare yourself for safety.

When you acquire new diving skills or techniques,

build on your new abilities carefully. In diving we speak

of staying within one's "comfort envelope." If you find

you are outside of your comfort envelope, you are proba-

bly well outside your skill level also. Stop your activity

and take stock. Decide what you should do to restore

your sense of assurance. Ascend to a shallower depth?

Stop the particular activity until a later dive? End the

dive? When you find you are not having fun, the first

thing you should do is ask yourself what you must do to

make it fun again. Un-fun is usually unsafe.

Do not dive beyond your fitness level. Being respon-

sible for your own safety also means that you must

assess your own physical ability to conduct any dive.

What is the distance to the dive site? Will it require a

long surface or underwater swim? Is there a current? If

so, will you be able to drift dive with the current, or will

you be required to move against the current? Are you

recovering from a recent illness or injury that will affect

your stamina? The wise diver does not willingly place

him or herself in a situation where the environment will

place excessive demands on his or her capabilities.

The activities of your Advanced Scuba Diver coursewill introduce you to many tools that you will use in

your future diving career. You may decide to explore

some in greater depth with specialty course training.

Whatever the activity for your dive, remember that

good preparation and planning are necessary elements

in diving safety.



C H A P T E R

N a v i g a t i o n





1. Review basic underwater navigation, includingthe techniques for "natural" and compass

navigation.

2. Learn about the equipment used for underwater

navigation.

3. Be introduced to more complex navigational pat-

terns and advanced techniques.

4. Learn various methods to accurately measure

distance underwater.

5. Learn how to "fix" your position on the surface.

6. Explore a typical Advanced Scuba Diver course

navigation dive.

I N T R O D U C T I O NOne way to perform like an excellent diver is to

navigate effectively. When you can end a dive at a prede-

termined location, you not only feel good, but you con-

serve a lot of time and energy. You also benefit from

increasing your navigational abilities because they are

part of other diving activities such as finding an offshore

reef, limited visibility diving, night diving, and search-

ing. Let's expand on the navigational principles you

learned as a beginning diver and add some new ones.

To get to an unfamiliar place on land, you probably

consult a map, determine where you are and where you

want to be, and then follow a course to reach your desti-

nation. Along the way you become acquainted with vari-

ous landmarks. After a couple of trips, you can travel to

the same location without a map.

Similar principles can be used for underwater navi-

gation. Charts, which are nautical maps, can provideinformation. It is best to follow a predetermined course

on your dives and use underwater landmarks to help

you maintain your bearings. Although there are no

streets for you to follow, you can use a compass as a

directional reference. In diving, you can also use depth

to help determine where you are. After making a couple

of dives in an area, you should get a feeling for where

you are.

Several navigational techniques will be introduced

in this chapter. You will have an opportunity to practice

these in one or more navigational dives. Also, you will

apply your navigational skills in the other dives of your

Advanced Scuba Diver course.

E Q U I P M E N TFor most applications, you will use a depth gauge, a

timing device, and a diving compass for navigation

underwater. The other piece of required equipment is a

clear, aware mind. Learning to navigate underwater is

similar to learning to find your way in the woods. Atfirst, all trees and hills look the same. For the most part,

there are no street signs or distinctive architectural

structures underwater, and even if there were the dis-

tance you can see is limited to 60 meters (200 feet) or

less, even in the best of conditions. But you have aids.

Your depth gauge can tell you where you are on the bot-

tom contour; your compass can tell you in which direc-

tion you are going.

In your entry-level course you practiced a basic use

of a compass. With a compass as your guide, you swam

a reciprocal course, returning to your starting point. As

an Advanced Scuba Diver, you will learn to take bearings

with a compass and use bearings and distance swum to

navigate more complex patterns. In order to do this, you

need to know more about compasses and their features

than "point, set, swim."

A compass is a magnetized needle that rotates on a

pivot point. When it can swing freely, the ends of the

needle will point towards the earth's magnetic poles.

Many compasses have a disc mounted on the needle or

on a magnetic ring, and the entire "compass card"rotates. An arrow printed on the card indicates magnetic

north. The earth's magnetic poles are not in the same

location as its geographic poles, so some variation

between north, as shown by the compass, and true north

is normal. Normally, this variation is not critical for div-

ing since you are navigating within a limited area. You

will learn more about magnetic variation in your Master

Scuba Diver course (figure 3-1).



C h a p t e r 3 - N a v i g a t i o n

bearing from the compass. A bezel or rotating collar on

the compass will have a set of index marks that can be

aligned with the pointing end of the needle or card. By

aligning the lubber line with your body and your direc-tion of travel and then rotating the bezel marks to align

with the needle, you are able to read your bearing as

well as mark the reference position of the needle.

Conversely, if you set the bearing, rotate the compass to

line up the compass needle and the bezel index, and the

lubber line will show the desired direction. For reference,

north (that is, magnetic north) is 0°, east is 90°, south

is 180°, and west is 270°.

The single essential feature that allows a compass

to be used in diving is that its case is liquid-filled. If the

compass had an air-filled case, increasing pressure on

descent would compress the case and prevent the needle

from rotating freely.

There are three basic compass design models: direct

reading, indirect reading, and side reading. The way you

take or set a bearing is different for each (figure 3-2).

A direct reading compass is marked 0° to 359°

around the edge in a clockwise direction. On a needle

compass, the degrees will be marked on a rotating bezel.

On a card compass, they will be marked directly on the

card with the card's north arrow marked 0°. To deter-mine a bearing with a direct reading card compass,

F I G U R E 3 - 2 . Y O U W I L L P R O B A B L Y H A V E A N O P P O R T U N I T Y T O U S E D I F F E R E N T C O M P A S S D E S I G N S D U R I N G Y O U R D I V I N G C A R E E R .

F I G U R E 3 - 1 . P A R T S O F A C O M P A S S

Compasses have other common features that you

may remember. The lubber line is a reference line that is

etched or marked somewhere on the compass. When the

lubber line is aligned with the axis of the boat or the

user, it indicates the course or bearing the user will fol-

low. If the bearing to the objective is known, the bearing

can be set on the compass and the lubber line followed.

If you want to obtain a bearing to a destination, point

the lubber line towards the target point and read out the




point the lubber line in the direction you want to travel,

let the needle point to magnetic north, and your bearing

is read directly under the lubber line. A needle compass

is similar, except that you rotate the bezel to align 0°

with the north end of the needle. Your bearing is read at

the lubber line.

An indirect reading compass has fixed markings of

0° to 359° in a counterclockwise direction around the

edge of the compass body. The degree markings do not

rotate, and 0° is permanently aligned with the lubber

line. When you take a bearing, the compass needle or

the compass card points to the bearing in degrees. The

reading is "indirect" because 0° is always in the direc-

tion of travel, and the compass needle points to the bear-ing. With an indirect reading compass, the bezel index

marks are used to register the relative position of the

needle so that you can easily realign the compass later

in the dive (figure 3-3).

A side reading compass is preferred by many divers

for its ease of use (figure 3-4). In a side reading com-

pass, the compass card has a skirt around its edge that is

marked 0° to 359° in a counterclockwise direction. A

window in the side of the compass body is in line with

the lubber line and displays the degree readings on the

skirt to the user. To obtain a bearing you look across the

compass and through the window. Your bearing is

shown in the window, and you need only remember the

bearing or note it on your slate for later reference.

Each of the three types of compass has its devotees,

and you will probably encounter all three in your diving

career. If you find one type easier to use, you should look

for it when you acquire your own compass.

M E A S U R I N G D I S T A N C E S U N D E R W A T E RTo navigate effectively, you need to be able to esti-

mate the distance you have traveled. If your dive site is a

hundred yards or a hundred meters offshore, you should

know when you have traveled that distance. When fol-

lowing a general course, maintaining correct headings

is one requirement, and estimating the distance for each

leg of the course is another. One of the sinking feelings

150°

Indirect Compass

Needle-Direct Compass

150°

Card-Direct Compass

F I G U R E 3 - 3 . D I R E C T A N D I N D I R E C T R E A D I N G C O M P A S S E S




Y O U R E Y E S O F F O F Y O U R T A R G E T .

in diving, is swimming a course and wondering as you

approach the end, "My heading must be wrong. I 'know'

I must have passed it." For some situations such as

searching, distances must be measured accurately. For

general diving, approximations of distance will usually

suffice. Several methods may be used to estimate dis-

tance. Let's look at some.

Most of us do not carry a long tape measure in our

BC pocket. Even if we did, deploying and retrieving it

would take a lot of time away from the enjoyment of our

dive. What other, easier measuring methods do we have

available?

Probably the most accurate way to estimate distance

is arm spans. For most people the distance between the

fingertips of their outstretched arms is about equal to

their height. If you are 180 cm (5' 11") tall, then this isabout the distance you can reach. A quick, but good

estimate of short distances can be made by stretching

your arms out alternately from touch-down point to

touch-down point as you swim.

The most common way to estimate distance is by

counting kick cycles. This is similar to counting your

paces on land. To use this method, you have to establish

the length of your personal kick cycle by swimming a

measured distance as you count kicks. (A measured dis-

tance is easy to establish in a swimming pool. If you are

in an open water setting you could use a measured

length of line, say 30 meters (100 feet), and anchor it to

the bottom.) One kick cycle is counted each time the

same leg comes down as you swim. When measuring

your kick cycle, do not try to rush or use an exaggerated

kick; use a kick that you can easily repeat just as you do

when measuring by paces on land. Divide the distance

swum by the number of kicks to find your distance per

kick cycle. Since measuring by kick cycles is an esti-

mate, you might want to round this number to some-

thing that you can easily remember and use in your

head. If your calculation is 94 cm per kick, 1 meter per

kick is probably close enough. Establishing the length of

your kick cycles is likely to be an exercise you will per-form in your Advanced Scuba Diver Course.

Another way to estimate distance is the time it takes

to swim the distance. This works if you are swimming

directly to your goal. But most of us like to take time out

to examine interesting sites, aquatic life, and objects; so

timed swimming tends to lose accuracy.

The same can be said about using air consumed

(psi or bar used) to measure distance. To use the air

F I G U R E 3 - 4 . A S I D E R E A D I N G C O M P A S S H A S T H E A D D I T I O N A L B E N E F I T O F L E T T I N G Y O U C H E C K Y O U R H E A D I N G A T A G L A N C E , W I T H O U T T A K I N G




consumption method to measure distance, you must

resolutely proceed toward your destination and not dilly-

dally along the way. Also, remember that your air con-

sumption rate increases both with depth and with exer-cise level. You should not only use a "standard" kick

and speed but also adjust your measurements as your

air consumption rate changes with depth.

With experience, many divers are able to use just

a "feel" for distance covered. Whatever method you

choose, the most important concept is to pay attention

to distance in order to find your dive site or to navigate a

pattern, such as a square, effectively.

F I G U R E 3 - 5 . O B S E R V I N G Y O U R S T A R T I N G P O I N T C A R E F U L L Y A T

T H E B E G I N N I N G O F Y O U R D I V E C A N M A K E I T E A S I E R

T O R E C O G N I Z E L A T E R .

N A T U R A L N A V I G A T I O NNatural navigation is the use of "landmarks,"

depth, and other visual aids to establish your position.You are familiar with the use of environmental aids for

references. Examples include the direction of light, for-

mations of reefs and sand ripples, depth and bottom

contour, currents and surge, and self-made references

such as silt trails and rock piles. Keen observation of

such aids can help you recognize areas you have visited

previously and can serve to help in determining where

you are.

There is more to natural navigation underwater,

however, than merely taking note of a few environmen-

tal aids. To be most effective, also apply the followingprocedures:

1. Use starting references. If you are diving from a

moored or anchored boat, carefully note your

point of origin after you descend and before you

swim off to begin your activity. In clear water,

you can even take advantage of a bird's-eye view

as you approach the bottom. It helps to study

charts of the area where you will be diving so you

can form a mental picture of the overall area. If

your dive site is on a slope, note the depth of the

anchor point at which you begin. If you return to

that depth as you navigate back to the boat, you

will be along the same contour as the anchor. If

you start at a known point, such as a rock out-

cropping, it will be easier to return to an area by

starting at the known reference on subsequent

dives. Concentrate on being able to recognize

your starting point underwater without having to

surface to reference the boat (figure 3-5).

2. Follow a pre-planned general course. Natural

navigation is much more effective when a pat-tern is followed than when you dive randomly.

Your course may be a square, a rectangle, a tri-

angle, or simply out-and-back; or you may plan

to follow a depth contour. Following a planned

course will better enable you to return to a start-

ing point or to relocate a specific area during

subsequent dives. It is not necessary to follow

the general course precisely. Some deviation is




permissible to investigate items of interest. When

you depart from your planned course, be careful

to note landmarks and the distance you have

deviated from your course. You should try to

maintain direction in a general heading for a

roughly estimated distance, then you and your

buddy should agree on a new general heading to

maintain your pattern.

3. Move forward by moving from aid to aid, and

look back frequently (figure 3-6). By moving

from known point to known point, your progress

will be more easily repeated. Pick out a distinc-tive object along your general heading and as far

away as visibility will permit. Work your way to

that object, and then repeat the process. As you

reach each point, glance back along the way you

have come to see what the previous aid looks like

when approached from the opposite direction.

This will be its appearance on your return. These

procedures help you become much more familiar

with an area than just merely noting underwater

landmarks from time to time.

4. Develop a desire to remember. If you want to

remember natural aids, starting points, and little

details to help you navigate more accurately, you

can. You should want the ability to navigate well.

If the desire is there, your awareness, perception,

and memory will be much greater than if your

interest is lackadaisical. By wanting to navigate

well, you will be able to develop the ability quick-

ly with practice and concentration.

C O M P A S S N A V I G A T I O NGood compass use is essential to most underwater

navigation. You will usually use a combination of com-

pass navigation with natural navigation techniques in

diving. Only seldom does a diver use one to the exclusion

of the other. You are familiar with how a compass works,

C A M E , F R O M T I M E T O T I M E .

F I G U R E 3 - 8 . D I S T I N C T I V E F E A T U R E S O F A R E E F F O R M A T I O N C A N L O O K E N T I R E L Y D I F F E R E N T O N Y O U R R E T U R N - L O O K B A C K T H E W A Y Y O U




F IG U R E 3 - 7 . W H E T H E R W R I S T O R C O N S O L E M O U N T E D , A L I G N I N G T H E C O M P A S S P R O P E R L Y I S C R I T I C A L T O A C C U R A T E N A V I G A T I O N U N D E R W A T E R .

and you know how to set a course on a compass and fol-

low it (figure 3-7). The following procedures will be

helpful to learn the practical application of the compass

for diving:

1. Have a starting heading and follow a general

course. Most of the time you will not use a com-

pass as a constant reference to follow an exact

heading. Instead, the instrument will serve as a

general reference. The compass is especially use-

ful in areas devoid of natural aids, such as sandy

bottoms. At the outset of every dive, you should set

an initial bearing as a point of reference. This

bearing may be the direction of shore, the direc-tion opposite to any current, or simply arbitrary.

The direction isn't as important as having a

direction of reference. Just as in natural naviga-

tion, you and your buddy can remain together

more easily and you will be better able to navigate

if you follow a pre-determined general course.

Again, the course need not be exact, but the

advantages of adhering to even a rough pattern

will become obvious with experience (figure 3-8).

2. Navigate from point to point. During natural

navigation you were instructed to move from

one environmental aid to the next. Except in

extremely limited visibility, the same principle

applies to compass navigation. The difference

between compass navigation and natural naviga-

tion is that compass navigation is more accurate.

When using the compass, look over it and along

the bearing and select the most distant object you

can see for your heading. Move to that object and

repeat the process. By using this "leap frog" tech-

nique, it will not be necessary to look constantlyat your compass, and you can spend more time

enjoying your dive.

3. Be aware of the effects of deviation. The compass

is a magnet, and it is attracted to ferrous metal

objects, other magnets, and electrical fields. Be

aware that the compass will not provide an accu-

rate reading when in close proximity (usually less

than a meter) to large attracting objects, including




not only shipwrecks but also steel scuba cylinders,

other magnets, or dive lights. You can test the

effects of your own equipment on your compass

by placing the compass on the floor, noting its

bearing, and seeing if deviation occurs as you

bring other pieces of your gear in proximity to the

instrument. You will then know how far away you

will need to keep various items in order to prevent

deviation and incorrect readings.

4. Remember to compensate for currents. When

moving with a current, you will cover more dis-tance than when moving against it. If you are

swimming across a current, the current will push

you sideways, and your actual direction of travel

(your heading) will not be the same as your indi-

cated compass course (your bearing). You must

swim slightly into the current to compensate for

its downstream push (figure 3-9).

Uncompensated Compensated

F I G U R E 3 - 9 . R E M E M B E R T O C O M P E N S A T E F O R C U R R E N T B Y

S W I M M I N G S L I G H T L Y U P S T R E A M .

F I G U R E 3 - 8 . S T A Y I N G T O G E T H E R W I T H Y O U R B U D D Y I S E A S I E R I F Y O U H A V E P R E D E T E R M I N E D A G E N E R A L C O U R S E F O R Y O U R D I V E .




S U R F A C E P O S I T I O N I N GAnother navigational technique is surface position-

ing. This procedure allows you to "fix" a position at the

surface so you can relocate an underwater site precisely.

For example, if you came across a wreck near the end of

a dive and wanted to return to it, you could surface over

the wreck and take some bearings to "fix" the position.

You could then return to the same position at the sur-

face by using your bearings and descend directly onto

the wreck.

There are several means to take a "fix," but the

most common ones are with bearings and ranges.

Bearings are simply course directions taken with a com-

pass. Ranges are sets of in-line objects, which, whenaligned, indicate a precise direction (figure 3-10).

From your position determine two visual lines to

permanent objects. The intersection of the lines exactly

"fixes" your location. The angle between them should

be as close to 90° as possible when taking a fix. A range

is established when you are able to line up two perma-

nent objects from you position. A range is more accurate

than a bearing, and should be used whenever possible.

The objects used for a range must be permanent struc-

tures, sunbathers on the beach will not do. The greater

the distance between the objects used for a range, the

more accurate the range will be. Any combination of

ranges and bearings can be used to establish a fix, buttry to have the intersecting lines as close to a right angle

as possible. Your ranges and bearings taken to "fix" a

surface position should be written on a slate and trans-

ferred to a permanent record after the dive. Memory

should not be relied upon for dive site relocation.

Now let's see how all of the navigational skills can

be combined to make you a more effective diver.

Imagine that you are looking for a wreck that is shown

on a chart and that the wreck is located a few hundred

feet from a reef that is directly offshore from a rocky

point. You can use both a compass heading and natural

aids to navigation to guide you from the rocky point to

the reef. You can then follow a compass heading that

you obtained from the chart as a guide to lead you to

the wreck. At the end of the dive you can surface directly

over the wreck and take a "fix" so you can swim directly

to the wreck for your next dive. Or, you may wish to visit

the wreck and return to your starting point without hav-

ing to make a surface swim. To do this, you simply fol-

low a reciprocal compass course from the wreck to the

F I G U R E 3 - 1 0 . A N A C C U R A T E " F I X " O F Y O U R P O S I T I O N C A N B E O B T A I N E D B Y U S I N G T W O R A N G E S ( O B J E C T S I N L I N E ) .




reef, then another reciprocal course from the reef to the

point where you entered. Natural aids also help keep you

on course.

O V E R V I E W O F A T Y P I C A LI N T R O D U C T O R Y D I V E

Your instructor may have more than one naviga-

tion dive planned for you. The first could be a natural

navigation dive in which you learn to measure dis-

tances, use natural navigation skills to locate yourself

throughout the dive, and fix a location using two

ranges. The second could be a compass navigation divein which you swim set patterns, such as squares and tri-

angles using your compass. A fun way to practice your

navigation skills is an orienteering treasure hunt in

which you find your next bearings and distances at each

point over a predetermined course. There are many

options for navigation dive challenges.

You and your buddy should plan the dive together

rso that you both are familiar with its objectives. It is

also a good idea to walk though your compass naviga-

tion on land in order to fix it in your mind and work out

any problems while you can easily discuss them. Decide

who will fill which role during the dive. It is usually

more successful for one member of the buddy team to

concentrate on being compass navigator while the other

keeps an eye out for landmarks, reference points, and

course markers.

Navigation is challenging, and it is fun to be able to

navigate successfully. Like most diving skills, it involves

learning the theory, practicing the skills under the super-

vision of an instructor, and becoming proficient through

practice. Set yourself a goal to become a good divingnavigator. These are skills you can use on every dive and

ones that you will need for future diving activities.



C H A P T E R

N i g h t a n d

L i m i t e dVisibility Diving





1. Learn the basic procedures for limited visibility

and night diving.

2. Understand the attraction that limited visibility

and night diving have for many divers.

3. Learn about the equipment used in limited visi-

bility and night diving activities.

4. Learn the special signals and communication

challenges of limited visibility and night diving.

5. Understand the precautions associated with limit-

ed visibility and night diving.


limited visibility and night dive.

I N T R O D U C T I O NYou may be wondering why anyone would want to

plunge into inky black waters at night or dive when the

visibility is hardly arm's length. When you find out why,

you may become just as excited about night and limited

visibility diving as the thousands of enthusiasts who

enjoy these activities regularly (figure 4-1).

Night diving has a special fascination and mys-

tique, but this only supplements the real motives for

descents into darkness. One attraction of night diving is

the opportunity to view aquatic animals. Many of them

that flee upon sight or keep their distance during day-

light hours can be approached quite closely during noc-

turnal dives. Because much of the life under water is

nocturnal, you also get to see animals that you might

not encounter during daytime dives.

By using a dive light at close range, you also get to

appreciate the rich, vibrant colors of the sub-aquaticworld at night. With no dilution from natural lighting,

the colors appear more intense than at any other time.

Your narrow beam of light also focuses your attention so

your awareness of detail is increased. Night diving is an

excellent way to enjoy the beauty of the underwater

world.

Limited visibility diving may not seem as attractive

as night diving, but in many areas visibility is always

limited. Visibility under water is considered limited when

you cannot distinguish another diver at a distance of 3

meters (10 feet) or less in a horizontal direction. There

are many things of interest in murky waters - wrecks,artifacts, fossils, etc. - and the only way to get to see

them is to know the procedures for diving under these

conditions. Turbid water is frequently nutrient-rich

water. Life is often abundant in areas where the visibility

is reduced by the vast amount of nutrients, but the ani-

mals that abound make diving in such areas exciting

and enjoyable (figure 4-2).

Your instructor will introduce you to the techniques

for diving at night and for diving in turbid water, but

don't expect to be proficient at either as a result of this

orientation. Your night diving ability will be limited to

circumstances similar to those in which you make your

introductory dive. Because such dives are usually con-

ducted in clear, calm water; at a protected, previously

F I G U R E 4 - 1 . N I G H T D I V I N G I S A N A C T I V I T Y R E G U L A R L Y E N J O Y E D

B Y T H O U S A N D S O F D I V E R S .



C h a p t e r 4 - N i g h t a n d L i m i t e d V i s i b i l i t y D i v i n g

F I G U R E 4 - 2 . M A N Y T I M E S T H E N U T R I E N T S T H A T F O S T E R A N A B U N D A N C E O F I N T E R E S T I N G A Q U A T I C L I F E L I M I T S T H E V I S I B I L I T Y .

dived site and with a well-known dive buddy, you have

much experience to be gained before you are proficient.

As with all special interest areas of diving, additional

training is recommended.

E Q U I P M E N TMuch of the extra equipment needed is common to

both of the topics of this chapter - night and limited

visibility diving. First let's examine the gear recom-

mended for night diving, then we'll note a few suggested

items for limited visibility diving.

Lights are an obvious requirement for diving at

night, but you may not be aware that several different

types are available. The principal requirement is a broadbeam main or primary dive light. A smaller back-up

light is also useful to make a safe exit in the event your

primary light fails during the dive.

The lights you use for diving must be designed

specifically for the purpose. A light which is simply water-

proof will not work well. The light must be designed to

operate not only in water but also under pressure. There

are many quality lights available at your local dive store,

and lights are often available for rent so you can find out

which type you prefer before purchasing your own. Dive

store employees or your instructor can help you select the

appropriate ones for your area (figure 4-3).

Pay particular attention to the handle configuration.

It may be a pistol grip or it might be designed to be held

by the body of the light itself. Make sure it will be com-

fortable to hold for a long period of time. Especially

F IG U R E 4 - 3 . D I V E L I G H T S C O M E I N A V A R I E T Y O F S T Y L E S T O M E E T

J U S T A B O U T A N Y N E E D .




when diving in colder waters and wearing neoprene

gloves. A neoprene glove's tendency to resist forming a fist

(such as would be required around the handle of a dive

light) can cause fatigue and a hand cramp over time(figure 4-4). Whether you choose a light that uses dispos-

able batteries or is rechargeable should be detennined by

how frequently you intend to use the light. The more

often the light is used, the more practical it becomes to

pay the extra expense for rechargeable batteries.

Rechargeable lights are also more ecologically friendly.

Good ideas also include buying spare bulbs at the time

you purchase your dive lights and keeping them with

your dive equipment so they're at hand if you need them.

A stretch able lanyard should be attached to your

dive light and your wrist in order to prevent its loss. The

stretchable feature (usually looped around your wrist) is

important so your hand can pull free in case the light

becomes entangled.

In addition to the dive lights designed for use

underwater, you will need lights for above water use.

These include lights to use for dive preparations as well

as marker lights to help you locate the entry/exit loca-

tion at the end of the dive. It is recommended that you

use regular flashlights for above-water use. This con-serves the batteries and bulbs in your dive lights. Also,

some dive lights will overheat unless cooled by immer-

sion in water. While you need not have additional dive

lights for the topside use, even your topside flashlights

should be of the "waterproof" type in case they acciden-

tally fall into the water (figure 4-5).

Lights to mark the entry/exit point on a shore dive

can be anything from lanterns to a pair of roadway

flasher types. Two lights arranged in a line perpendicu-

lar to the shoreline can form a range for you to follow

on your return. Another consideration is for them to be

distinctive so they won't be readily confused with other

lights in the dive area. Be careful to avoid the use of

lights that might resemble navigational aids, especially

flashing red, green, or white lights. Amber or yellow is a

good alternative.

F I G U R E 4 - 4 . W E A R A G L O V E A N D C H E C K T O S E E I F T H E L I G H T W I L L B E C O M F O R T A B L E T O U S E T H E W A Y Y O U W I L L B E U S I N G I T .




F I G U R E 4 - 5 . E X T R A L I G H T S T O I L L U M I N A T E T H E S T A G I N G A R E A A R E N E C E S S A R Y A F T E R T H E S U N H A S S E T .

A special type of light is also recommended for night

dives - a safety light to mark you and your position.

These help divers keep track of one another in the water

and also allows a dive boat to spot a diver at the surface

even if the diver's other lights have failed. A glowing or

flashing light is attached to each diver, usually on or

near the tank valve. They are available as battery-pow-

ered strobe lights or with a long, translucent front lens or

as chemical glow sticks. The glow tube produces "cold"

light through chemical reaction (figure 4-6). A glass

tube of one chemical is sealed inside a plastic tube con-

taining another chemical. Bending the outer plastic

tube until the glass tube inside breaks, allows the chemi-cals to mix and produce light. Safety lights make it easy

to spot divers in and under the water, and their use is

highly recommended on all night dives. In many loca-

tions using them is standard practice and considered a

requirement. However, they are really only "marker"

lights and do not produce sufficient light to be useful for

other purposes. Be sure to wait to activate the safety light

until just before you begin the dive.F I G U R E 4 - 6 . C O L D L I G H T F R O M A C H E M I C A L G L O W S T I C K M A K E S

A N E X C E L L E N T N I G H T D I V E R L O C A T O R .




F I G U R E 4 - 7 . I T I S I M P O R T A N T T H A T B U D D Y L I N E S B E H A N D H E L D A N D N O T M A D E F A S T W I T H A K N O T O R C L I P , I N C A S E O F E N T A N G L E M E N T .

Luminescent gauges are preferred for night diving.

A luminescent gauge will "store" light energy from a

dive light that is shined on it and glow for many min-

utes. It is unusual to find gauges that do not have lumi-

nescent properties or, in the case of dive computers, an

ability to illuminate the display.

Other useful equipment includes items that are

hopefully part of your regular gear set. These items

include a good dive knife, gloves, a diving compass, and

a whistle for surface signaling. A low-pressure inflator,

that has become standard equipment, allows buoyancy

to be controlled with just one hand, which is helpful,

since one of your hands will be occupied with a dive

light. A surface float with a "down" line is also recom-

mended unless you are diving from a boat. Consider

attaching a glow light to the float. It is not a good idea

to carry additional gear such as a camera until you

have acquired training and are comfortable while nightdiving.

Except for the use of dive lights, limited visibility

diving equipment needs are the same. A dive light might

be helpful, but back-up lights, surface marker lights,

and chemical glow lights are not required. The use of a

"Buddy Line," a short line held between two divers to

maintain contact, is often helpful to prevent separation

in murky water (figure 4-7).

P R O C E D U R E S A N D P R E C A U T I O N SNight diving can be every bit as enjoyable as diving

in the daytime. There are even advantages to diving at

night. It is cooler for gearing up, there usually are fewer

divers to stir up an area, and your light allows you to be

seen as well as to see. In order to enjoy the underwater

world, however, you do need to abide by the following

procedures and be aware of a few new hazards.

Night diving is usually better when done from a

boat, but shore dives are perfectly acceptable. However,

rock strewn entry areas profuse with plant life that

makes the footing treacherous even in daylight should

be avoided at night. The best shore diving areas are

those where reefs are just offshore from a smooth, unob-

structed entry. Diving in familiar areas is recommended.

Even then, it is a good idea to dive the known area the

same day prior to a night dive to evaluate the conditionsand to reacquaint yourself with the site. No matter where

the dive is based, it is helpful and advisable to have

someone remain above water during night diving activi-

ties as a contingency against mishap.

The planning process for a night dive is even more

important than for regular dives. Because of the height-

ened excitement from anticipating a night dive and the

added challenge of working in the dark you should be




sure to give extra attention to all aspects of your dive

plan. Make sure your dive lights have fresh batteries or a

full charge.

As you prepare to dive, be sure to review signals withyour buddy. Standard hand signals can be used, but

remember that they must be given in front of a light in

order to be visible to others. Signaling with your dive

light is unique to night diving. A large "O" formed by

moving the light in a slow circle is the long distance

version of the "OK" signal. Rapid wiggling of the light

from side to side is often used to signal, "Attention" or

"Look here." Distress is signaled by extending the light

out to one side and moving the light rapidly in long,

exaggerated 180 degree arcs overhead. These light sig-

nals are useful both at the surface and underwater.

Be sure to note some distinctive feature on your

buddy like the color of his or her mask, so you can easi-

ly recognize him or her underwater at night. It is not

uncommon for dive teams encountering one another to

accidentally switch partners during a dive or even return

to a different boat!

Other preplanning items are the same whether day

or night diving is being conducted. Discuss and agree on

the general course to be followed to improve buddy coor-

dination. Agree in advance which buddy will navigate

for the first half of the dive as the partner points out

things of interest. The roles can then be reversed on a

reciprocal course during the second half of the dive.

Before you attempt a night dive, you and your buddy

should be practiced at successfully staying together dur-

ing daytime dives.

As stated earlier, lights should be set up to help you

identify the exit point prior to your dive. When using

shore lights that are already in place, only lights that are

fixed and can be relied upon to remain on until afterdiving operations end should be used. For example,

street lamps are usually reliable, but a residential porch

light might be switched off. If you have set up your own

pair of lights as a range, consider it another good reason

to have someone remain on shore to ensure the lights

are still in place at the end of the dive.

Before you enter the water to begin your night dive,

double check to be sure your light is attached to your

wrist by a stretchable lanyard. This will prevent it from

being dropped after your entry and while you make

last minute preparations at the surface. Experienced

night divers facing a long swim usually want to leavetheir lights off until they reach the dive site. This will

help avoid having the light flashing about on the sur-

face and from depleting your batteries prior to the dive.

Dive preparations also include checking your gear for

proper adjustment, and setting a compass heading for

reference.

Whenever possible descents should be made on a

line or on a gradually sloping shore. With no external

references at night, it is easy to become disoriented. The

disorientation can range from not knowing which way is

up, to extreme dizziness and must obviously be avoided.

The line serves as a reference and prevents the problem.

Your depth gauge should also be checked frequently as

you descend. Buoyancy control is just as important as on

any daylight dive. Adjust for neutral buoyancy so you

can stay clear of the bottom. This will keep you from

bumping into the reef or bottom dwelling animals and

stirring up silt (figure 4-8).

Once submerged and on your way, the following

procedures and precautions become important:

1. Keep excursions short. It is neither necessary norwise to cover large areas during a dive at night.

Enjoy the small things.

F IG U R E 4 - 8 . M A I N T A I N I N G N E U T R A L B U O Y A N C Y W I L L A L L O W

Y O U T O A V O I D L A N D I N G O N T H E B O T T O M ! N T H E

W R O N G P L A C E .




2. Monitor your air supply, direction, and buddy

more frequently than usual. It is easier to stay

together than it is to find each other at night. Be

sure to surface with an adequate reserve of air inyour cylinder in case your underwater navigation

is off.

3. If separated from your buddy, remain stationary

and turn slowly in a circle while looking for your

buddy's light or glow light. If unsuccessful, move

in the direction in which your buddy was last

seen, stop and look again for light. If your buddy

is not located within one minute, ascend to the

surface, looking about as you ascend. Once at the

surface, continue to look for your buddy whileturning completely around with your light off.

Do this for one full rotation at the surface and

again while looking underwater toward the bot-

tom. It will be easier to see the glow of your

buddy's locator light or glow stick with your dive

light turned off. Your buddy should be duplicat-

ing your actions, so you should be able to reunite

quickly and continue your dive.

4. Be sure to keep your light beam out of the eyes of

other divers. Shining your light in their eyes

compromises their night vision for a short period.

When you shine a light toward other divers, point

it toward their waists.

5. If your light fails while diving, there is no cause

for alarm. Your buddy has a light and you should

both have back-up lights. First, make sure your

primary light is really defective by checking the

switch and by shaking the light. If the light is

inoperative, switch to your back-up light and fin-

ish the dive. Even if all of your lights fail, you

can still make a normal ascent. By remainingcalm on the bottom and allowing your eyes to

adjust to the darkness for a couple of minutes

you will find that there is usually enough avail-

able light to allow you to see things dimly. You

and your buddy can then ascend and terminate

the dive.

6. Control your anxiety. Night diving may seem

spooky at first. But this can be half the adven-

ture! Moving shadows created by your light will

soon cease to startle you. You may see a surprised

animal trying to get away from the brightness of

your lights. As you become interested in things,your anxieties will lessen. Take it easy and enjoy

yourself.

When you and your buddy agree to ascend, it is best

to do so on the line you used for descent. If the line can't

be found, you can ascend without becoming disoriented

by holding your depth gauge in front of you in one

hand and shining your light on the gauge and your

exhaust bubbles as you ascend. The gauge helps you

determine your ascent rate, and the bubbles provide an

up and down reference.

As a general rule that applies to most dive excur-

sions, all of your equipment should be kept in place

until you are clear of the water after a dive. This will

help prevent the loss of gear.

The procedures and precautions for night dives also

apply to limited visibility dives except for use of lights. A

dive light can be useful in murky water, but it may help to

hold the light to one side to reduce the glare from light

reflected off particles suspended in the water ("backscat-

ter"). Perhaps the best use of a light in limited visibility is

for examining objects at close range. Other limited visibil-ity procedures include moving slowly and with one hand

extended in front of you. In extremely turbid water, it is

necessary to feel your way along the bottom, but diving in

such conditions is not usually enjoyable, and a dive

should be aborted if the visibility is that poor. Use of a

buddy line or holding hands can help prevent separation.

Disorientation can be even more of a problem in turbid

water than in clear water at night. The use of a

descent/ascent line or following the contour of the bottom

to and from shore is suggested. Both techniques help you

avoid being in mid-water with no reference.


Your night dive may be preceded by a daytime dive

at the site. You might engage in a social activity while




waiting for darkness or you may reassemble at the

staging area after dark. The objective is to be familiar

with the area. Your instructor will brief you on the par-

ticulars and recap the main points to keep in mind. Alot of attention will be given to your equipment and

your lights. If you do not own or are not ready to pur-

chase a good dive light for this dive, you can probably

rent/hire one from you local NAUI affiliated dive center.

Depending on your instructor's preference, you may

need to use a chemical light or battery powered locator

light.

During the actual dive your instructor may choose

to lead all of the dive teams as a group, or you may be

assigned to dive by teams in a specified area. Either way,

your descent will probably use down-line or follow the

contour of the bottom so you will have a continuous ref-

erence. The underwater tour follows your descent, and

time passes quickly as you become engrossed in the way

things appear as your dive light cuts into inky dark.

Your instructor may have you settle to the bottom,

remain motionless, and turn off your lights to see what

it is like without them. Soon you will be able to make

things out and will discover that the glow lights put out

quite a bit of light when they are the only source. Your

instructor will turn on his or her light as a signal for

you to turn your lights back on and resume the dive.

Until then you should remain motionless on the bottom.

Your ascent will also be controlled via the line or

bottom contour. Surface lights will help you recognize

the exit area.

Afterwards, even the discussion of the dive is special

at night. If there is insufficient light to allow you to fill

out your logbook, be sure to complete it at the earliest

opportunity and to have it signed by your buddy and by

your instructor.A limited visibility introductory dive usually consists

of dive teams following an assigned heading or course

underwater. The use of buddy lines may be introduced.

Your primary goals will be to navigate accurately and to

maintain buddy contact.

Your opportunities to dive can be increased once

you are trained to dive competently at night or in limit-

ed visibility. After discovering what either or both of these

activities is like, you will probably want to develop your

abilities further so you can take advantage of opportuni-

ties that may arise. Ask your instructor about a Night

Diving specialty course or one for Limited VisibilityDiving. Now that you know it is fun to do these activi-

ties, why not have some more fun and gain the training

and experience that will enable you to engage in them

safely without supervision?



C H A P T E R

I n t r o d u c t i o n t o

D e e p e r D i v i n g





1. Learn the basic procedures for deeper water

diving.

2. Learn about the hazards of deeper water diving

and how to mitigate their potential to cause

problems.

3. Be introduced to the equipment used for deeper

water diving.

4. Learn the steps of planning and preparing and

the procedures and precautions for a deeper

water dive.


deeper water dive.

I N T R O D U C T I O NAs you gain experience in diving, you are almost

certain to be encouraged to dive at sites that have depths

in excess of your qualifications. Deeper diving is gener-

ally defined as dives to depths greater than 18 meters

(60 feet). Satisfactory completion of the NAUI Advanced

Diver course can prepare you to undertake no-required-

decompression dives at depths up to 40 meters (130 feet)

as long as the diving occurs under circumstances simi-

lar to those experienced during your training. Divers are

often tempted to dive deeper for adventure and for the

challenge, but more meaningful objectives are encour-

aged. Good objectives might include exploration, study-

ing aquatic animals, or photographing exotic sites, such

as wrecks, which happen to be located in deeper water.

The point is that deeper diving should be justified, and

not done just for the sake of going deep.

It can be exciting and rewarding to descend fartherbelow the surface to observe and explore new places.

However, you must be aware of the hazards of deeper

diving and be prepared to cope with them. This involves

careful planning and preparation, proper training, spe-

cial equipment, experience and special procedures. In

this chapter you will become acquainted with each of

these areas. This information will help you prepare for

an introductory experience at a depth greater than 18

meters (60 feet). A single experience will not necessarily

qualify you to make deeper dives without leadership

supervision, but it will acquaint you with deep diving

procedures and will help you appreciate why additionaltraining for deeper diving is a good idea.

P O S S I B L E H A Z A R D SAs you already know, pressure increases with depth.

This results in an increased rate of air usage due to the

greater density of the air you breathe. The increased

density of the air increases the effort needed to exchange

air in the lungs. Poorly maintained regulators can easily

amplify this problem and cause feelings of "air starva-

tion".

When wet suits are worn in colder waters, increas-

ing and decreasing pressure can also cause significant

changes in buoyancy due to compression and expansion

of the gas trapped in the neoprene rubber. Wet suit com-

pression reduces insulation and increases heat loss.

Combined with the colder water usually found at depths,

increased heat loss can quickly lead to chilling. As the

suit expands during ascent the increasing buoyancy

must be compensated for in order to control your ascentrate.

Higher nitrogen levels contribute to a greater likeli-

hood of decompression sickness occurring. Also, nitro-

gen breathed under higher pressures can produce

Nitrogen Narcosis, which affects judgment and, there-

fore, safety.

In addition to these physical considerations, know-

ing that you are diving deeper can lead to increased lev-

els of stress or feelings of anxiety.

Since the risks and potential hazards increase withdepth, greater caution must be used when diving deeper.

This demands more thorough planning and prepara-

tion, extra equipment, and special procedures. By know-

ing and applying deep diving techniques, you can

increase your safety and your enjoyment whenever you

dive to deeper depths. But you must know what to do

and how to do it, and you must exercise the necessary

self-discipline to follow the recommended practices.



C h a p t e r 5 - I n t r o d u c t i o n t o D e e p e r D i v i n g

E Q U I P M E N TWe recommend that your regular diving equipment

include an extra second stage on your regulator, a low

pressure inflator on your buoyancy compensator, a dive

computer and backup instrumentation, and an under-

water slate. Your equipment should also be in good con-

dition and in excellent working order.

An extra second stage can simplify air-sharing situa-

tions underwater, but for deeper diving a complete back-

up scuba system such as a "pony bottle" with its own

regulator is recommended (figure 5-1). Your instructor

will probably show you a back-up system, which has the

advantage of being a completely separate source of air

for either the person wearing the unit or for anotherdiver in need of air. Since you are only being introduced

to deep diving you will not be required to have a back-up

unit, but you should be familiar with them and know of

their desirability for dives to greater depths.

Instruments are important for diving, but they are

essential for deep dives. First and foremost-as always-is

the submersible pressure gauge. It is required on all

dives, but is critical for deep dives to help you avoid run-

ning out of air.

Depth gauges are also essential, as are watches

or dive timers (figure 5-2). A reliable depth gauge is

absolutely necessary for dives planned using dive tables.

F I G U R E 5 - 1 . A C O M P L E T E L Y R E D U N D A N T A I R S U P P L Y I S R E C O M -M E N D E D F O R D E E P E R W A T E R D I V I N G .

F I G U R E 5 - 2 . D E P T H G A U G E S C O M E I N A W I D E V A R I E T Y O F D E S I G N S W I T H M A N Y D I F F E R E N T F E A T U R E S . Y O U R L O C A L N A U I A F F I L I A T E D D I V E C E N T E R

C A N H E L P Y O U M A K E A G O O D C H O I C E .




F IG U R E 5 - 3 . D I V E C O M P U T E R S A L S O U S E A V A R I E T Y O F D E S I G N S WITH M A N Y D I F F E R E N T F E A T U R E S . O N E B E N E F I T I S T H E A C C U R A C Y A N D R E L I A -

B I L I T Y O F I N F O R M A T I O N T H A T I S A U T O M A T I C A L L Y R E C O R D E D .

The best accuracy is usually achieved with a dive com-

puter (figure 5-3)- A dive computer is not only more accu-

rate, it also continually monitors your dive status and pro-

vides essential information including remaining dive time

based on calculations of your absorbed nitrogen levels.

Dive computers help divers avoid decompression

sickness by providing reliable and accurate measures of

depth and time. If you use a dive computer is important

to have read the manufacturer's instructions for its use.

It is also a good idea to have used the computer on shal-

lower dives to familiarize your self with its operation.

It is essential that each member of the dive team be

able to independently monitor his or her own depth and

dive time, whether with a depth gauge and a watch or

timer or with a dive computer. Sharing depth and time

instruments with your dive buddy is risky and should be

avoided on all dives regardless of depth.

Another useful, but not critical, instrument is thecompass. The ability to use the compass to navigate

effectively underwater can be valuable on deep dives. It

is not easy or wise to surface for bearings, therefore, a

compass for each diver is recommended as well as com-

petency in its use.

Having extra cylinders available for deep dives is

highly recommended. Divemasters some times place an

extra cylinder with an attached regulator in the water toF IG U R E 5 - 4 . D E C O M P R E S S I O N B A R S W I T H E X T R A C Y L I N D E R S A R E

E A S IL Y D E P L O Y E D F R O M A B O A T .




be used in the event of an out-of-air emergency. When

diving from a boat, the spare cylinder/regulator is hung

below the vessel at a depth of about 5 meters (15 feet). It

is wise to also have a couple of spare cylinders of air

readily available at the surface (figure 5-4).

When diving in poor visibility or when making

training dives, a descent/ascent line, sometimes referred

to as a "down line," is recommended. The line should

be at least one centimeter (three-eighths inch) in diam-

eter, weighted at the bottom, and marked at 3 meter (10

foot) intervals. This line provides reference, control, and

a base for the extra scuba unit and for decompression.

The set-up procedures for the line and recommendations

for its use will be covered in the procedures section of

this chapter.Many specialized forms of diving are best undertak-

en from a boat, and usually deeper diving is no excep-

tion. A boat is an excellent surface support station. It is a

good idea for the boat to be equipped with a radio for

emergency communications and with a depth sounder.

Emergency equipment is recommended for all

dives, but it is even more strongly suggested that a first

aid kit and oxygen be at the dive site for deeper dives

(figure 5-5). Oxygen is of significant value in the event

of decompression sickness.

It is not unusual for low light levels to be encoun-

tered in deeper water, so a dive light might be another

useful item. The chapter on night and limited visibility

diving explores the many considerations when using or

choosing an underwater light.

As you can see, there are quite a few equipment

requirements for deep diving. You may not be required

to have all of the gear just described when you make

your introductory dive because you will be under the

supervision and direction of your instructor, but you

should be aware that this equipment is necessary when-

ever you and your buddy plan to dive "deeper" without

the benefit of an instructor being present.

P R E P A R A T I O NThe deeper you intend to dive, the more preparation

required. You begin by making sure that you have

yourself prepared for the dive with proper training. You

must also have a good, confident feeling about the dive.

F I G U R E 5 - 5 . E M E R G E N C Y O X Y G E N F O R U S E I N F I R S T A I D H A S B E C O M E A S T A N D A R D P R A C T I C E .




F IG U R E 5 - 6 . T E C H N I C A L D I V I N G I S A D I S C I P L I N E D A P P R O A C H T O O V E R T A K I N G D I V I N G T H A T H A S A M U C H H I G H E R D E G R E E O F R I S K T H A N

T R A D I T I O N A L D I V I N G .

If you are apprehensive about the situation, it is fine to

suggest an alternative dive. Personal preparation also

includes general good health and physical fitness, cur-

rency in skill proficiency, adequate rest the night before

the dive, and proper nutrition prior to the dive.

Abstinence from drugs that alter your physical or mental

state or affect your decompression obligation is essential.

You need to feel fit, both physically and mentally, when

intending to make a deeper dive.

You have already read that your equipment needs to

be in proper working order, but we are re-emphasizing

the point here due to the importance of properly func-tioning gear at depth.

Planning for the dive needs to be more thorough

than usual. Extra equipment is needed. Emergency pre-

paredness requires more attention. You need to know the

location of the nearest operational recompression cham-

ber, how to contact the appropriate medical and/or

chamber facility, how to make arrangements for any

needed treatment and how to get someone there who is

in need of treatment. Finally, your necessary agreements

need to be exacting and well understood.

A review of the NAUI Dive Tables or your dive com-

puter manual is in order. Re-familiarize yourself with

them by reading the information on the dive planning

and the dive tables in the NAUI text, NAUI Scuba Diver.

You must be able to use the tables correctly when the

dives you are making are actual dives rather than just

problems posed on paper. Your instructor will probably

review them as part of your Advanced Scuba Diver

Course. A more thorough review plus some new infor-

mation on the dive tables is included in the NAUI MasterScuba Diver and Deep Diving Specialty courses. For the

diver who plans to exceed the limits of traditional recre-

ational diving, NAUI's Technical Diving Division quali-

fies instructors who deliver "cutting edge" training (fig-

ure 5-6). NAUI members have been pioneering diving

since 1960. It is not surprising that they were the first to

embark on "extreme" dives and develop training proto-

cols for those who wish to follow.




TNT = TNT = TNT =

F I G U R E 5 - 7 . T H E D I V E P L A N N I N G W O R K S H E E T I S U S E F U L T O P L A N A H E A D A N D F O R R E C O R D I N G D A T A A F T E R T H E D I V E .

When planning your deep dive, it is important that

you complete the "Dive Plan" section of your NAUI

"Dive Planning and Recording Worksheet" on the back

of your NAUI Dive Tables (figure 5-7). This contingency

information provides instantaneous time limit informa-

tion in the event that you should exceed your planned

depth. For deep dives, it is recommended that an

expanded contingency plan be written on your slate and

taken along on the dive. This provides previously deter-

mined information for various times plus various

depths. This approach is preferred to attempting to refer-

ence the dive tables underwater where errors are more

likely to occur.

These are the minimum preparations for deeper

dives, but don't be misled into believing that this is all

there is to going to increased depths in diving. There are

more procedures, more things to be learned and addi-

tional training requirements to be met before you

should make excursions approaching the maximum

recommended 40-meter (130-foot) depth limit for tradi-tional recreational diving. It is important now for you to

learn and apply the basics of preparation and planning

during this Advanced Scuba Diver course so you can dive

with confidence to deeper depths. In your own diving,

stay within your "comfort envelope" by advancing grad-

ually towards greater depths. You should understand

why advanced specialty training is necessary if you

desire to dive even deeper. Diving beyond 40 meters

(130 feet) is to enter the realm of "technical diving,"

where additional special procedures and gas mixes are

employed, and mandatory decompression is a virtual

certainty.

P R O C E D U R E S A N D P R E C A U T I O N SUpon arrival at the dive site and determining that

conditions are suitable for the dive, you should check

emergency communications systems and determine that

they are functional. Telephones or radios are of no value

if they do not work.

When applicable, set up a "down line" and an air

cylinder with a regulator attached. Place the tank and

regulator at the precautionary decompression stop depth

of 5 meters (15 feet). This extra tank is often called a

"hang-off" tank. It should be turned on to ensure that it

is full and that the regulator is functioning properly, but

it should then be turned off to prevent loss of air if theregulator should free-flow while the tank is hanging on

the line. All of the divers in the group should be informed

that they will need to open the valve on the hang-off

tank if it is needed. The down line should be vertical and

taut. This is accomplished by placing weights on the bot-

tom of the line and suspending it above the bottom. If

the line is suspended from a surface float rather than a

boat, an anchor and line can be rigged from the weights




F IG U R E 5 - 8 . P R E D I V E E Q U I P M E N T C H E C K S A R E A L W A Y S A N I M P O R T A N T S T E P A N D E V E N M O R E S O W H E N E X E C U T I N G A D E E P E R W A T E R D I V E .

at the end of the line to the bottom.

Whenever possible and practical, it is recommended

that surface support personnel be present during deeper

dives and that these individuals be divers. Their function

is to assist in the preparations to dive, to keep a record of

diving activities (times, depths, etc.), and to do any and

all physical work required following the dive (retrieving

the down line, pulling the anchor, etc.). The divers

should keep physical exertion to a minimum following

a deep dive because activity increases the chances of

decompression sickness, as does drinking alcoholic or

caffeinated beverages and taking hot showers.

It is a good idea to check your equipment three times

before entering the water for a deep dive (figure 5-8). Youshould inspect it yourself after suiting up, your buddy

should check it, and the surface support person should

also look you over before you enter the water. It is safer

and easier to make corrections to equipment above

water than it is underwater. Upon entering the water and

agreeing with your buddy to begin your descent on the

down line, again make a quick check of your gear to

make sure it is secure and properly oriented, then check

your timing device or computer to make sure it is set to

begin measuring elapsed time. Your descent should be

controlled. Descend slowly, feet first and eye-to-eye with

your buddy. Stop occasionally to recheck your gear and

to test your buoyancy. If you sink with a full breath, you

need to add air to your buoyancy compensator.

Upon reaching the planned depth, test your buoy-

ancy again by letting go of the down line briefly. If you

are too heavy or too buoyant, grasp the line while you

make adjustments, then test your buoyancy again. Do

not leave the descent line until your buoyancy is correct.

Next, select the desired direction in which to begin your

dive and take a moment to orient yourself to the sur-

roundings and to the down line. Note the direction of any current and be aware that the current at the bottom

may run in a different direction than the surface cur-

rent.

As the dive progresses, you should frequently refer-

ence your proximity to the ascent line. Also reference

both your instruments and your buddy's. If there is a dif-

ference in the readings on your gauges compared to

those on your buddy's gauges, use the more conservative




reading. In other words, use the deeper reading gauge

for the determination of your present depth. If you are

both using dive computers, end your dive when the more

conservative computer reaches its limit.It is important that you proceed at a slow, easy pace

during deeper dives. Breathe continually. Avoid "skip

breathing," and avoid heavy exertion. As you monitor

your air, keep in mind that one-half of your air supply is

for your bottom time, which includes your descent, and

one-half is for your ascent, decompression stop (safety

or emergency) and for contingency purposes. For dives

to even deeper depth, the rule is modified to one-third

for descent and bottom time, one-third for ascent and a

precautionary decompression stop, and one-third for

contingency.

A slow, controlled descent and a slow, easy pace on

the bottom can also reduce the likelihood of experienc-

ing nitrogen narcosis. There are numerous and various

symptoms of narcosis. If you experience any strange or

unusual feelings, you should immediately signal your

buddy and ascend until the feelings are alleviated. Even

if you just feel uncomfortable, you should signal your

buddy and ascend until you are again at a comfortable

depth. An established rule of diving, and one which is

especially important for deeper diving, is that anyone

can call an end to a dive at any time and for any reason.

If your buddy signals you to ascend, respond at once

rather than trying to communicate that you are still

fine, have time, air, etc. When in doubt, ascend and end

the deep dive.

One of the more popular types of deep diving is

"wall" or "drop-off" diving (figure 5-9). At many loca-

tions in the Caribbean, the continental shelf drops off

steeply into extremely deep water quite close to shore.

The vertical walls of the drop-off offer spectacular div-ing, but those who dive these areas need to follow rec-

ommended procedures and practices. It is common to

anchor the boat near the edge of the drop-off. Buoyancy

must be trimmed precisely before venturing out over the

deep water. With proper buoyancy control, there is a feel-

ing of exhilaration as you hang suspended in space on a

wall dive. This type of dive is often led by a divemaster or

guide. You should not go deeper than the guide. If you

F I G U R E 5 - 9 . D E E P E R W A T E R D I V I N G I S C O M M O N L Y C O N D U C T E D

O N D R O P - O F F S O R " W A L L S . " I T I S I M P O R T A N T T O

F O L L O W I N S T R U C T I O N S A N D T H E D I V E P L A N T O

A V O I D P R O B L E M S .

do, you can cause the dive to be shortened for everyone

in the group, and you won't be very popular after the

dive. A good practice is to move away from the boat

along the wall at a pre-determined depth and to return

to the boat at a shallower depth. There are other proce-

dures that will be explained to you. Pay attention during

the briefing and follow the instructions, which are for

your benefit and safety.

It is important that you adhere closely to your dive

plan on deep dives. One of the conventions for deeperdives is that a dive plan should not be changed during

the dive with the exceptions, of course, to dive shallower,

ascend sooner, or respond to emergency situations.

Remember, "Plan your dive, then dive your plan." This

is more important than ever for deeper dives.

Your ascent should be made on the down line,

which provides a reference, control, and a place to carry

out precautionary decompression stops. Your rate should




not exceed 9 meters (30 feet) per minute or the rate

specified by your dive computer. This rate is much slow-

er than most people realize, so monitor your progress by

watching your depth gauge and counting slowly or com-paring your ascent to elapsed time. You should stop at 5

meters (15 feet) to decompress for a minimum of three

minutes, even if your total dive time is well under the

no-decompression limits. This is a good safety precau-

tion. It is good practice, also, in the event that a manda-

tory decompression stop should ever be required.

Maintain yourself at the decompression stop level and

keep activity to a minimum. Sometimes a weighted bar,

called a "decompression bar" or "deco bar," is used to

provide a better base for decompression than the down

line. The decompression bar can accommodate more

divers than a down line, and its use is common practice

for charter dive boats.

In order to relocate the down line for your ascent,

you will need to dive nearby, or you will need to navigate

accurately. It is best to stay close to and in sight of the

ascent line. If you are unable to locate the down line for

your ascent, you will have to perform a hovering safety

stop and surface without the reference and control pro-

vided by the line. This could be hazardous under condi-

tions that warranted the use of a vertical descent/ascent

line. If a deep dive is being made from shore, you may

be able to swim toward shore and make your safety

decompression stop on the bottom in shallow water.

Deep dives from shore also allow you to follow the con-

tour of the bottom for descents and ascents, but result in

less time at depth because the angled descent requires

more time than a vertical descent on a down line.

When a dive has very short bottom time, such as a

quick dive to free a fouled anchor, the dive is termed a

"bounce dive." Such dives can increase the chances of decompression sickness occurring and are to be avoided,

especially following a deep dive or any dive approaching

the no-decompression limits. It is better to spend one,

continuous length of time at a depth than it is to spend

an equal amount of time at that depth with a couple of

trips to the surface included.

Upon surfacing from the water after completion of

your precautionary decompression stop, note the time

for the start of your surface interval, signal the surface

support person that you are "OK," and make your way

to the exit. After exiting the water and removing your

gear, take it easy for a while. Avoid exertion, hot showers,alcohol, and drinks containing caffeine. You should also

wait at least 12 hours, longer if your dive is one of a

series of repetitive dives, before flying in an airplane. Any

hard work, such as pulling the anchor or carrying heavy

equipment, should be performed by people who were not

involved in the dive.

Perhaps you feel that with all of this knowledge and

with the experience of a couple of dives beyond 18

meters (60 feet) you are ready to handle any kind of

deep dive. There is much more you need to know. Your

deep diving ability as an Advanced Scuba Diver is limit-

ed to the depth of your training. Gradually increase your

depths to stay within your comfort envelope and multi-

tasking ability. Plan to obtain additional training if you

are interested in deep diving or have a need to make

dives to deeper depths. Before you rush off to make deep

dives on your own, remember all of the equipment you

need in order to make deep dives and remember your

responsibility to the diving community to conduct your

recreational dives safely.


The planning and preparation for your introductory

dive may be assigned to you. As you set up and prepare

for the dive, you do so under the supervision and direc-

tion of your instructor. Equipment such as the down line

and the hang-off tank is provided, but you may be

required to prepare it for use. A review of the NAUI DiveTables is usually included, and may be part of the brief-

ing for the dive. A more thorough review and additional

information on dive tables theory and usage is included

in the NAUI Master Scuba Diver course. The briefing will

also include instructions on activities for the dive, which

may involve recording the readings of depth gauges for

comparison, noting the effects of pressure on various

items, buoyancy loss measurements, an aquatic life sur-



vey, a guided tour, or a combination of these. A precau-

tionary decompression stop will be included, and you

may have the opportunity to practice additional precau-

It is important for an introductory deep dive to be

well organized and coordinated, so be attentive during

the briefing and ask questions for clarification. Find out

such details as whether you should go around divers

who have stopped on the down line during descent or

whether you should hold your position above them.

You will learn more about deeper diving during the

discussion following the dive. Another review of the dive

tables is usually included in the debriefing. Remember

to log the dive and have your log book signed by yourbuddy and by your instructor.


tionary decompression stops on the down line.



C H A P T E R

C o n s e r v a t i o n

a n d A q u a t i cL i f e S t u d i e s





1. Be introduced to conservation and aquatic life

studies.

2. Learn about biological study techniques.

3. Be introduced to the equipment used in aquatic

life studies.

4. Learn the procedures for conducting biological

studies.


aquatic life study dive.

A Q U A T I C L I F E S T U D I E SThis chapter provides an introduction to conserva-

tion and aquatic life studies. The study of fresh water

animals and plants is known as limnology. The study of

marine plants and animals is known as marine biology.

You will learn some of the techniques used by scientists

in the fields of limnology and marine biology.

There are millions of species in the waters of our

earth. Some people are more interested in studying these

life forms than others, but all divers should at least be

able to recognize certain types of animals for safety rea-

sons. There are benefits from studies of aquatic life. You

will learn how to see things you would otherwise over-

look, you will be able to satisfy some of your curiosity

about some plants and animals, and you will be able to

explain some of the aspects of aquatic life to others.

This type of diving is also a very interesting way to

develop other valuable diving skills such as navigation.

Perhaps the most interesting part of all, however, is the

interest you will develop when learning about relation-

ships between animals, their traits, their uses, and theirrole in the environment. You will develop a greater

appreciation for nature, you will learn to identify ani-

mals, and you will view hunting, collecting and preserv-

ing of plants and animals from an entirely different per-

spective.

After your introduction to aquatic life studies, you

won't be qualified to participate in scientific expeditions,

but you will have an idea of how much interest you

have in this area. There are plenty of books, classes, and

opportunities for you to learn more and to further devel-

op your ability to do research as a diver.

A c t i v i t i e sBiological study techniques vary. Typical activities

include quantitative counts, comparison studies, surveys,

controlled observations, tagging, collecting, and preserv-

ing. You might study all life forms in an area or focus

on only one. It can be fun to learn the habitats, special

relationships, distinctive characteristics, roles, behaviors,

dangers, and names of various creatures. Techniques

include timed or controlled searches and counts, general

and transect surveys, use of special scientific equipment,

and more. Generally, though, studies involve an organ-

ized approach to learning about a particular life form in

a designated area.

E q u i p m e n tThe equipment for underwater studies of aquatic

life ranges from an underwater slate to sophisticated

electronic measuring devices. You are not likely to be

exposed to elaborate equipment during your dives, but

there are some simple items of gear that you may use

and with which you should be familiar. The activity usu-

ally involves the recording of a lot of data, so a good

underwater slate and pencil or a clipboard with water-

proof paper is a must (figure 6-1). Professional

"research divers" even use waterproof tape recorders

with special mouthpieces that enable them to speak

underwater. Slates for aquatic studies are usually larger

than the general use ones available for recreational div-

ing. Rulers and measuring devices may also be useful

for determining sizes when collecting data.Standard techniques involve the studying of a spe-

cific area, so equipment such as marker buoys, lines,

anchors, bottom markers, counting grids, measured

lines or poles, etc. are frequently required. The idea is to

mark off an area on the bottom and to limit the study to

the area that has been defined.

Diving instruments are important. A compass is

needed for navigation, establishing transects, and posi-



C h a p t e r 6 - C o n s e r v a t i o n a n d A q u a t i c L i f e S t u d i e s

F I G U R E 6 - 1 . A S L A T E W I L L B E N E C E S S A R Y T O R E C O R D Y O U R F I N D I N G S O N A N A Q U A T I C L I F E S T U D Y D I V E .

tion fixing. A depth gauge is necessary to record data

about habitats, and a thermometer is useful. A dive

watch allows activities to be coordinated and findings to

be keyed to time.

A dive light is helpful for peering into dark places

and allowing colors to be observed. Many colors in the

spectrum are removed from natural light by absorption.

The deeper the depth, the more colors are absorbed until

only blue or violet light remains. By providing artificial

light in close proximity, the colors of an object in deep

water can be seen.

Collecting equipment such as nets, collecting guns,

traps, collecting bags, and tagging equipment may be

called for. One type of collecting gun is the "slurp gun,"

which is a vacuum-type plastic tube that "slurps" ani-

mals into a chamber.

An underwater camera can be a useful tool to theresearch diver (figure 6-2). A picture can literally be

worth a thousand words when documenting animal

behavior or habitat. You will learn more about under-

water cameras and photography in the chapter on the

topic later in the book.

When a large area needs to be surveyed, a diver's

sled or a Diver Propulsion Vehicle (DPV) may be used to

allow systematic searching at speeds faster than those

F I G O R E 6 - 2 . F O R U N D E R W A T E R R E S E A R C H A N D S T U D Y , A P I C T U R E

C A N B E W O R T H A T H O U S A N D W O R D S .

possible by swimming. A DPV is a battery-operated

device with a motor and a propeller that the diver holds

onto or rides (figure 6-3). Another device for surveying




F I G U R E 6 - 3 . D I V E R P R O P U L S I O N V E H I C L E S ( D P V ' S ) C O M E I N D I F -

F E R E N T D E S I G N S A N D A R E U S E F U L W H E N Y O U N E E D

T O C O V E R G R E A T E R D I S T A N C E T H A N I S C O N V E N I E N T

W H I L E S W I M M I N G .

F I G U R E 6 - 4 . N O T E T H E S U R R O U N D I N G S W H E N Y O U F I N D A

S U B J E C T F O R S T U D Y .

large areas is a diver's sled, sometimes referred to as an

aquaplane. This is a board with handles which is towed

behind a boat and held onto by a diver. The board can

be tilted to provide directional control. Since the force on

the diver can be quite great, towing speeds must be slow.

A seat may be attached to reduce the strain on the diver's

arms. A quick disconnect device is a necessary safety fea-

ture. Use of this latter piece of equipment requires train-

ing and practice, and should be used only by highly

experienced divers.

P r o c e d u r e sOrganization is a necessary first step. The partici-

pants in the study need to know what to look for, where

to look for it, what data to obtain, and the techniques to

be used. Communications and coordination are a neces-

sary part of organization. Special signals may be used,

and will need to be introduced and agreed upon. Once

everyone is organized, some of the following procedures

may prove useful.

As your dive progresses, you will find that it is easy

to look at something underwater and yet not see it.

Many life forms are experts at camouflage. Light levels

are often low as well. Unless you make a conscious effortto observe and to identify, you may not see many of the

creatures you are looking for. The skill of keen observa-

tion is one that can be developed. One key is to impress

into your mind the contour of the animal you are seek-

ing. As you look about, keep this contour in mind and

you will be surprised at how the creature you seek will

seem to jump from its background as its contour match-

es your imagined one. You should also focus narrowly

on things as you come upon them and not let your eyes

move idly from one thing to another.

Once you find an animal, note the circumstances.

Is the creature among rocks, on sand, in open water?

What is the depth? This will help you to find others of

the same species. Note the size and color. Fix the animal

in your mind by naming it, by discussing it as soon as

possible, and by using a reference book (figure 6-4).

Seeking one type of plant or animal to the exclusion of

all else is usually preferable to looking for a variety of

life forms.



F I G U R E 6 - 5 . S U R V E Y S S H O U L D A L W A Y S B E C O N D U C T E D I N B U D D Y P A I R S .

After your dive, take time to reflect upon the experi-

ence. Leisurely go over it in your mind and picture the

significant things you saw. The more you ponder your

experience, the more you will learn and retain, and the

more effective you will be on your next dive. Finally,

transfer your observations and circumstances from your

slate and record them in your logbook. Writing rein-

forces your memory.

Much aquatic life is not out in the open where it

can be easily viewed. You must either discover the hiding

place of the animal or attract it. Dive lights are very use-

ful for peering into holes and crevices and beneath over-

hangs.

Baiting animals with food is a common practice as

a means to observe them. The desire for food is often

greater than the fear an animal may have for your pres-

ence. Your goal is to observe the animal within its envi-ronment without harming the creature. The use of

lights and bait can help you to achieve this goal.

During biological studies, searches for plants and

animals are usually controlled. Depending on the

underwater terrain, the density of the objects being sur-

veyed, and other factors, more or less methodical forms

of quantitative studies can be used. For high-density sit-

uations, such as a sand dollar bed, a square formed

from plastic pipe may be used. The square is placed over

a representative section of the animals being studied and

the number of animals inside the square is recorded. By

measuring or estimating the total area covered by the

animal population and multiplying it times the number

of animals per area covered by the square, the total pop-

ulation can be estimated.

To survey animals on a larger scale, such as starfish

on a sandy bottom, a different method is used. A

"Transect" line of a specific length-say 20 meters-is

stretched and anchored along a selected heading on the

bottom. The divers making the count swim up one side

of the line and down the other using a measured pole to

delineate the survey area. One end of the pole is kept

next to the line, and all animals passing beneath the

pole are counted. In this way, multiplying the density

per known area times the estimated total area canapproximate the total population. For increased accura-

cy, the search line can be moved parallel by two pole

lengths one or more times and the survey repeated to

determine a more accurate density average.

Another method of surveying using the transect

method is for divers to follow an assigned heading

through an area and count all of a certain species

encountered on that course. The area viewed needs to be

C h a p t e r 6 - C o n s e r v a t i o n a n d A q u a t i c L i f e S t u d i e s




determined, and will depend on the distance covered, the

animal being studied, the visibility, and other factors. By

having several teams of divers make parallel transect

counts in an area, and by knowing the dimensions of the area being covered, fairly accurate estimates of pop-

ulation size can be made.

It is important that all surveys be performed by

buddy teams of divers (figure 6-5). Solo diving is not

permitted for obvious safety reasons. Also, teams of

divers increase the opportunities for sightings of the

plant or animal being sought. For better accuracy, it is

usually a good idea for each diver to count separately

and for either the higher number or an average of the

two counts to be used.

In addition to density studies, data recording is also

important. You may want to record the depth, tempera-

ture, bottom composition, and other information when-

ever you find an animal. It is also useful to note any

special relationships the animal may have with other

animals, any unusual behavior, and distinctive charac-

teristics. It is fun to try to determine what role the ani-

mal plays in the overall environment. The more you

learn about an animal, the more interesting it becomes.

By recording information for later reference, you will

learn more and get more enjoyment from your diving.Some activities, such as comparison studies and

tagging projects, are beyond the scope of recreational

diving, but you can imagine the challenges and rewards

possible when such undertakings are successful. Your

experience in learning a little about biological studies

may provide you with an opportunity to participate as a

volunteer diver in a local environmental study.

Additional training will increase your capabilities and

your opportunities.


As is usually the case in the Advanced Scuba Diver

Course, your instructor will provide you with informa-

tion on the dive and you will need to prepare a dive

plan. You will probably meet at the dive site and receive

an orientation to the area and a briefing on the dive

activity. Your study may consist of finding and identify-

ing a list of plants and animals common to the area, or

you may be asked to conduct a survey of an area for oneparticular species. Collecting is usually discouraged in

order to conserve aquatic life.

Post-dive activities include a review of the dive

objective and the procedures used, a compilation and

examination of the data collected, a discussion of any

problems experienced during the dive, suggestions from

your instructor, and logging of the dive. Aquatic study is

frequently one of the most enjoyable dives in the

Advanced Scuba Diver Course.



C H A P T E R

S e a r c h a n d

R e c o v e r y





1. Learn the basics of finding and recovering objects

lost underwater.

2. Be introduced to the general procedures of search

and recovery operations.

3. Learn how to rig a found object for lifting to the

surface.

4. Learn about the equipment used on search and

recovery.

5. Understand the techniques and precautions of

search and recovery.


search and recovery dive.

I N T R O D U C T I O NYou won't be a diver for long before you will lose

something and need to find it or before someone asks

you to find and recover something they have lost in the

water. Most non-divers assume that because you are a

diver you can easily find something that has been lost

underwater. This usually isn't the case unless you have

been trained in at least the basics of searching for and

recovering objects. Finding things underwater requires a

proper approach for success and safety. This is also true

of recovery. This chapter will introduce you to this very

useful activity area and will provide you with a few

basics that will help you find and recover lost equip-

ment, items dropped from a boat while at anchor, and

lightweight objects found while diving. The techniques

described will also help you in searching for good dive

sites. This chapter, however, is not intended to prepare

you to salvage heavy objects or to engage in search andrecovery operations that would be considered commer-

cial or professional. The scope of this introduction is

limited to the basics of the topic, practice of simple

searches, and the use of a small "lift bag," which will be

described later.

NAUI Search & Recovery Diver Specialty courses are

available to help you learn more complex aspects of this

topic, and you can greatly increase your capabilities in

this area during the NAUI Master Scuba Diver course.

Your initial studies and introductory dive will help make

your attempts to locate and retrieve items safer and more

effective. You will also find that your search and recoverytraining involves the application of many diving skills

that improve as you apply them for a new purpose. You

will become a better underwater navigator, for example,

and will also develop increased underwater awareness.

G E N E R A L P R O C E D U R E SWe will divide the general procedures into those for

searching and those for recovering.

The first fundamental of searching for an object

under water is to define the area to be searched and to

mark the starting point. The sooner the point at which an

object has been lost can be marked, the better the chances

for recovery. Some experienced divers carry a marker buoy

on all dives just so they can mark the location of an

object that has been found or one that might be dropped.

In this way, they are able to relocate and recover objects

easily. Having a marker buoy handy in your gear bag at

F I G U R E 7 - 1 . M A R K E R B U O Y S A R E I N D I S P E N S A B L E F O R S U C C E S S -

F U L S E A R C H A N D R E C O V E R Y O P E R A T I O N S .



C h a p t e r 7 - S e a r c h a n d R e c o v e r y

F I G U R E 7 - 2 . W I T H O U T A S T A R T I N G P O I N T A N D B O U N D A R I E S T H E O C E A N I S A L I M I T L E S S A R E A I N W H I C H O B J E C T S L O S T A R E S E L D O M F O U N D .

the surface is also a good idea. If someone drops some-

thing overboard, the immediate marking of the spot will

increase the chance of recovery (figure 7-1).

After determining the starting point as accurately as

possible, define the area to be searched. This will depend

on many factors, but unless you define the limits of the

search, you will not be able to search systematically,

which is critical to success (figure 7-2). The boundaries

of the area to be searched are sometimes identified with

buoys, but other limits such as depth can be used.

The next step is to select an appropriate search pat-

will be introduced in the Techniques and Precautions

part of this chapter. Search techniques are taught in

greater detail in NAUI Master Scuba Diver and in NAUI

Search and Recovery Diver Specialty courses. For nowyou need only understand that the type of pattern to be

used is affected by visibility, bottom conditions, the size

of the object, currents, and other considerations. The

ability to choose the best pattern for a given situation

may well determine whether or not the objective of the

search is quickly met or leads to frustration. Much of

search and recovery training is about learning search

patterns and practicing them.

With the starting point marked, the area defined,

and the pattern selected, the next item of concern is to

keep track of the areas that have been searched. It is

obviously a waste of time to meticulously search the

same area twice. Marker buoys can be used to designate

the limits of the search. In still water on certain types of

bottoms it is even possible to draw lines on the bottom to

mark your progress. Training and experience will help

you select ways to keep track of the areas searched.

The final basic item to be considered for searching

may seem obvious, but it is frequently not followed and

causes frustration. The principle is to mark an object

once it has been found unless the object is light enough

to be recovered immediately. A marker buoy should be

attached to the item and deployed to the surface. All too

often the object of a search has been located, and afterthe divers have surfaced to report the find they have

been unable to relocate it! That can be frustrating, espe-

cially when it is so easily avoided.

If an object is small and light, recovery is simply a

matter of picking the object up and returning to the sur-

face. But when the object weighs more than about ten

kilograms (twenty-two pounds), a "lift bag" should be

used to raise the item to the surface. A typical lift bag is

tern.Types of search patterns and how to conduct them




shaped like a small hot-air balloon. Adding air to the lift

bag provides the buoyancy used to lift objects underwa-

ter. Divers are often tempted to simply grasp the object

and inflate their buoyancy compensators and use them-selves as "human lift bags," but this is a dangerous

practice that should be avoided. If the diver with the

excess buoyancy accidentally drops the object, a danger-

ous, uncontrolled ascent can occur and result in injury.

Even if the object is retained during the ascent, holding

onto it occupies the diver's hands and may prevent the

diver from controlling buoyancy as the air in the BC

expands. Never risk being a "human lift bag."

To salvage an object that has been found and

marked, the first step is to "rig" the item securely.

Rigging is the term used to describe the attachment of

ropes, cords, and straps, between the object to be sal-

vaged and the lifting device. You may be required to tie a

line to an object, so knowledge of and the ability to tie

several knots will be required. The main idea to be kept

in mind when rigging an item is that preventing the

item from coming loose during the lift is essential for

safety.

The next salvage fundamental is to match the lift-

ing force of a lift bag to the weight of the object being

recovered. A lift bag is a bag that can be filled with air to

provide a buoyant force for the lifting. More on lift bags

will be presented in the Equipment part of this chapter.

When a lift bag is used to raise an item, the lifting

capacity of the bag should not greatly exceed the weight

of the object. If it does, the air inside the bag will expand

during ascent, accelerate the lift, and the lift can get out

of control. By matching the capacity of the bag to the

weight of the object being recovered, the bag will be full

or nearly full at the start of the ascent, the excess air will

simply bubble out the bottom of the bag, and the ascent

will take place at a fairly constant, controlled rate. You

will learn how to estimate the size of the lift bag in the

Techniques and Precautions part of this chapter.

The next principle of recovery is to maintain con-

trol during the lifting process. Even when the object is

properly rigged and when the appropriate size of lift bag

is being used, control is required. You must control the

entire situation, including yourself, your buddy, other

divers present, and the lift itself. The procedures for

doing this are also presented in the part on Techniques

and Precautions.

Become familiar with these basic principles, whichare now summarized for you. No matter how much you

learn about search and recovery, you will find that these

apply.

1. Define the area to be searched and mark the

starting point.

2. Select the appropriate search pattern.

3. Keep track of the areas searched.

4. Mark the position of an object when it has been

found.

5. Securely rig the object to be lifted.

6. Match the lift bag capacity to the weight of the

object being recovered.

7. Control the lift.

EquipmentMany of the items of extra equipment used for

search and recovery have already been mentioned.

Continue reading to learn more about this equipment.

Marker buoys are available in various sizes and

configurations. They are small and compact so they can

be easily carried by divers. Well-designed marker buoys

obtained from a dive center are recommended over

homemade. Most buoys have nothing to stop their line

from completely unraveling (make sure you've checked

that the bitter end of the line is secured to the buoy or

you can lose the float in the current) when deployed

underwater resulting in the excess knotting at the sur-

face or drifting down current. This can be unavoidablewhen used to mark an unexpected find. Once you have

regained the surface tie off the line, but allow a little

slack to accommodate waves and tide changes. You

don't want your marker buoy to be hidden underwater

because you made the line taut and the tide has come in

when you return to begin the recovery phase.

Underwater slates are useful for communications as

well as for information recording. Time can be saved

B A S I C P R O C ED U R E S O F S E A RC H AND RE COV E RY:



F IG U R E 7 - 3 , L IF T B A G S C O M E I N A V A R I E T Y O F D E S I G N S A N D S I Z E S . IT I S I M P O R T A N T T O M A T C H T H E B A G T O T H E I T E M B E I N G L IF T E D

and frustration avoided when coordinating with yourbuddy if you can simply write a message to convey your

point. Draw the search area on the slate before you start

and mark off each area as you search it.

Even better is the use of underwater radio commu-

nications so that you and your buddy and others on the

team can simply talk to each other. These devices are

readily available, reliable and becoming a popular addi-

tion to many recreational divers equipment.

To define an area to be searched or to keep track of

what has been searched, surface floats are often used.

These are a form of marker buoy, but are larger and

more positive indicators than smaller marker buoys

designed to be carried by a diver. The larger float is easi-

er to see at the surface, and can deploy a heavier anchor

that provides better holding power. However, surface

floats can be anything from a plastic jug to a specially

designed buoy as long as the purpose of defining and

maintaining the search area is fulfilled.

Perhaps the most specialized item of equipment

for search and recovery operations is the lift bag (figure

7-3)- The bags are made from different materials, andthe type of material isn't important as long as the bag

holds air under water. The neck of the bag is fairly nar-

row and usually has a strap attached for rigging the

bag to the object being lifted. A desirable feature on

a lift bag is a "dump valve" - a manually operated

valve that allows expanding air to be vented from the

lift bag during ascent. This is one way in which a lift

can be controlled.

An extra source of air should be used for inflating alift bag under water. Use of the diver's primary regulator

second stage is not recommended. The regulator could

become entangled in the lift or get caught as the lift

begins to ascend. Being pulled to the surface with no

source of air is a potentially hazardous circumstance

and one that can be avoided by use of an extra source of

air. The use of a separate cylinder of air to fill a lift bag

is recommended, although use of a regulator's extra sec-

ond stage is permissible if care is taken to avoid the

potential for entanglement and adequate air supply is

available. The potential for entanglement can be

reduced if one diver holds the bottom of the lift bag

open while the other adds air to the bag. Also, do not

push your hand up inside the lift bag while adding air.

T E C H N I Q U E S A N D P R E C A U T I O N SYou are now familiar with the basics of what to do,

but you need information on how to do it. This part of

the chapter will explore the appropriate techniques touse and will help you learn about potential hazards

involved with search and recovery so you can avoid

them.

Again, your first step is to mark the starting point.

The use of a marker buoy was suggested, but what if you

don't have one? Then a "fix" of the position as described

in the chapter on navigation should be taken as quickly

and accurately as possible. Even if there is absolutely





F IG U R E 7 - 5 . P A R A L L E L S E A R C H P A T T E R N

F IG U R E 7 - 8 . E X P A N D I N G S Q U A R E S E A R C H P A T T E R N

nothing visible that can be used as a reference, you

should still write down any information that can help in

establishing the search area. What is the depth? What

time is it? Which way is the current flowing and how

strong is it? If you were diving in the vicinity, what was

the bottom like? Were any underwater landmarks or dis-

tinctive features nearby? Information such as this can

help a great deal and may lead to successful search, but

don't trust it to memory. Write it down.

The second step is to select an appropriate search

pattern. However, you don't always have to conduct an

underwater search. In some situations, snorkeling on

the surface is all that is necessary. No matter which tech-

nique you use, your search needs employ the appropri-

ate pattern and be well planned (figure 7-4,5,6,7).

There are two basic types of search patterns: circu-

lar and straight line. There are countless variations of

these basic types, but we will look at only a few of them

that are useful for areas where the bottom is relatively

unobstructed.

A circular search is most useful when the point of loss is rather well defined. The idea is to extend a line

from a marked center point and search in ever-widening

circles until the lost object is located. The technique

usually uses a heavy weight as the hub for the sweeps,

but your buddy can serve as the anchor point while you

make the circular passes. It is necessary to know when a

circle has been completed. This can be done by placing

an object on the bottom, marking the bottom, noting a

F I G U R E 7 4 . C O N T O U R S E A R C H P A T T E R NF IG U R E 7 7 . C I R C U L A R S E A R C H P A T T E R N




compass heading, or by being signaled by a buddy who

remains at the hub and signals completion of a circle by

tugging on the line. It is important that the line be kept

taut during the sweeps. The amount of area searchedduring each sweep depends on the visibility and the size

of the object. There are many variations to the basic cir-

cular sweep, and your instructor will explain the exact

approach you will use in your training. A circular sweep

is the easiest and fastest search method available, but it

does require a search line and good coordination

between the divers involved.

Straight-line searches are used when the exact point

of loss is less well known. The general concept is to sweep

back and forth over an area in a systematic pattern until

the object is located or until the area has been thorough-

ly covered. The pattern is usually executed by following

compass headings. Distances for various legs of the pat-

terns are measured by time or by counting kicks.

A more precise variation of a straight-line search

pattern uses semi-fixed search line to control the

searchers' progress. The line is deployed along the bot-

tom and its ends are weighted in place at the limits of

the search area. The buddy team then searches along

the length of the line. When they reach an end, that end

is moved sideways a short distance, and the team search-

es back along the line. The process is repeated, moving

each end of the line in turn until the object is located or

the search area has been covered. This "jack-stay" or

"z" search pattern is very thorough because there is

extensive overlap as the line is searched back and forth,

but it is also time consuming.

It is a good idea to practice a search pattern by

walking through it on land before attempting it under-

water. This way it allows you to discuss the signals and

coordination needed before you submerge and are forcedto rely on slates and hand signals.

After executing a pattern and finding nothing, the

pattern may be repeated by establishing a new starting

point and repeating it. It should minimally overlap part

of the area covered by the previous search. The overlap

increases efficiency and helps prevent any of the search

area from being missed. It should now be rather obvious

why you need to begin at a known point, search a

known area, and finish the search at a known point.

Only when these criteria have been met can a systematic

search be conducted.

It is important that buddy contact be maintained

during searches. There are different ways to accomplish

this depending on the type of search. For circular sweep

searches, buddy contact can be maintained with line

pull signals, but the signals used need to be agreed upon

in advance. During compass course searches, the divers

should swim together with one diver navigating the pat-

tern and the other doing the searching.

When the object of a search has been located and

the divers need to surface to obtain the lifting equip-

ment, its position should be marked. It is a good idea if each member of a dive team has a marker buoy. One

can be used to mark the starting point for a search, and

the other can be used to mark the object once it is locat-

ed. If no marker buoy is available, employ the same pro-

cedures for marking a point of loss. Write down perti-

nent data before surfacing, and establish ranges and/or

bearings to get a "fix" on the location as quickly as pos-

sible upon surfacing. Also note your location in relation

to the buoy marking the starting point.

If a lift bag is needed, its capacity should approxi-

mate the weight of the object. Lift bags are usually rated

in terms of weight of lift. For example, a 20 kilogram

bag will lift 20 kilograms of weight (50 pound bag will

lift 50 pounds of weight). Unfortunately, lift bag capaci-

ties are not divided into very small increments; but for-

tunately many bags have "dump valves" for venting

excess air during lifts. As long as control can be main-

tained by venting expanding air on ascent using a bag

with more lift than is necessary is acceptable. It is unac-

ceptable to use a bag that is much too large and which

has no provision to reduce the excess buoyancy.The next step is to rig the object for lifting. The lift

bag may have a strap and a clip, and this simplifies the

rigging procedure. When possible, place a full wrap or

"round turn" of the strap around the object before

securing the end of the strap rather than simply passing

the strap around the item. You may need to secure the

object to the lift bag with line, and you will need to be

able to tie some appropriate knots (figure 7-8). As a




minimum you should be able to tie: Two Half Hitches, a

Bowline, and a Sheet Bend. These knots will be useful

for you to know for other applications besides diving.

Two Half Hitches are useful for securing the end of

a line to something (also useful is a Clove Hitch) or for

making a slipping loop in the end of a line when tied

around the line itself.. A Bowline forms a non-slipping,

easy-to-untie loop in the end of a line. Because a square

knot may work loose if continually flexed by wave

action, a Sheet Bend is often preferable for joining two

lines together particularly if they are of different circum-

ferences. For most rigging purposes, these knots should

meet your needs. Remember that desirable features of

any knot are not only that it is easy to tie, but also that

it holds well and is easy to untie.

With the proper size lift bag rigged securely to the

object, you are ready to begin the lift. Signal your buddy

and make sure the area is clear of other divers. Use the

extra air source to put air into the lift bag. Proceed slow-

ly, adding a small amount of air at a time and noting

the effect. If you just keep adding air until an object

starts off the bottom, you will have more buoyancy than

is needed for the lift and it will be difficult to control. Try

to get the object neutrally buoyant so it hovers just off

the bottom. You can then check the rigging to make

sure it is holding properly when it is supporting the full

weight of the object. Start the lift on its way when you

are ready by simply pushing the object upward a little.

The expansion of air from the pressure reduction will be

enough to establish positive buoyancy. It is important

that you and other divers stay clear of the area below a

lift. You and your partner should ascend with the lift

and use the dump valve in the lift bag to maintain a

proper ascent rate. If the lift gets out of control by rising

faster than it should, let it go, swim horizontally awayfrom it, and surface. It is possible that the bag may clear

the water enough to dump air when it reaches the sur-

face, and the object will immediately sink. You do not

want to be underneath if this happens. In the event that

you vent too much air and the lift begins to sink, release

it, follow it to the bottom, add air and start again. Don't

try to support a sinking lift by holding it and swimming

or by trying to add air to it as it descends.

Bowline

Two Half Hitches

Clove Hitch

(End of Rope)

F I G U R E 7 - 8 , K N O T S

Single Sheet Bend




O V E R V I E W O F A T Y P I C A L S E A R C H A N D

You will need some extra equipment for this dive,

including a compass, a marker buoy, an underwater

slate, some line, and a lift bag. Your instructor may pro-

vide some or all of it or make arrangements for you to

obtain it. If you want to always be prepared to recover

small items underwater, you may see the value of pur-

chasing your own gear for this activity. Your local NAUI

affiliated dive center can aid you in selecting the equip-

ment, but be sure to point out that at present, you are

only interested in simple operations and in salvaging

lightweight objects.

When you arrive at the dive site, your instructor will

brief you on the area and the dive and explain in detail

the search and recovery procedures. You should practice

the rigging procedures and the search patterns on land.

Practice as buddy teams and use the opportunity to

establish any signals you might need under water.

The objects to be found and recovered may be

known to the instructor or may be placed in known

locations in advance with a marker buoy placed nearby

to mark the starting point. You will usually begin your

dive by swimming to the starting point and then search-

ing by teams. There may be several objects placed in the

area so each dive team will have an opportunity to find

and salvage something. If you are unsuccessful in your

first couple of searches, your instructor may interrupt

your searching, place you closer to an object, and have

you start again so you will be successful in finding an

item and so you will have the opportunity to salvage it.

So both members of a buddy team can gain experi-

ence, it is common to re-sink an item after it has been

recovered, for the diver who rigged it to unrig it, and forthe other diver to then rig the object and salvage it

again. The salvaged items may be brought to shore or

returned to the bottom - whatever your instructor

directs you to do.

After the dive you will meet and discuss what you

did and how well it went. Problems will be reviewed and

your instructor will offer suggestions to help overcome

them. Your log books should be completed and signed.

You will find that the time goes quickly on this

dive because it is interesting and fun. You will also

refine some diving skills, learn about a new dive site

and find out how well you like search and recovery as

a diving activity.

R E C O V E R Y I N T R O D U C T O R Y D I V E



C H A P T E R

W r e c k

D i v i n g




In this chapter you will:

1. Be introduced to the popular and challenging

activity of wreck diving.

2. Learn the possible hazards of wreck diving.

3. Be introduced to the equipment used by wreck

divers.

4. Learn about the procedures used by wreck divers.

5. Understand the legal and ethical issues associat-

ed with wreck diving.


wreck dive.

I N T R O D U C T I O NNearly everyone has dreamed of discovering an

ancient galleon filled with treasure. Just the thought of

finding gold and silver, jewelry, money, and other treas-

ures is exciting. The possibility does exist because more

than one fourth of all of the gold that has ever been

mined has been lost underwater. It is rare that treasure

is recovered, but Wreck Diving is one of the most popu-

lar diving activities for other reasons. Some ships are

even sunk purposely to form artificial reefs and interest-

ing dive sites (figure 8-1).

People dive on wrecks to collect relics and artifacts

(where it is legal), to use them as an interesting back-

ground for underwater photos, to hunt or observe the

abundance of life often found there, to pursue interestsin history or archaeology, or just for personal reasons

such as curiosity or fascination. There is an awe and

mystique about wrecks that seems to keep divers return-

ing to them (figure 8-2).

Finding wrecks isn't easy, even if you know their

exact location. And finding wrecks that are undiscovered,

challenges even to those who devote their lives to it.

There is always the possibility that you will come across a

wreck by chance, but such findings are rare. Even if you

should come upon a wreck site, you might not be aware

of it. The classic Spanish galleon wrecks depicted in

movies are not to be found in the sea. The elements and

the creatures of the ocean soon reduce a wreck to a pile

of rubble and hide it with a dense covering of growth.

However, shipwrecks can be preserved amazingly well in

fresh water.

Wrecks often occur because of the geographical

area. There are often dangerous reefs and strong cur-

rents that contributed to the sinking of the vessel and

with which divers must contend if they wish to visit the

site. Wrecks are frequently found at deeper depths,requiring careful planning and procedures. In the next

part of this chapter you will learn of many other poten-

F I G U R E 8 - 1 . S H I P W R E C K S H A V E A L W A Y S I N T R I G U E D D I V E R S A N D M A N Y L E A R N E D T O D I V E J U S T F O R T H E O P P O R T U N I T Y T O D I V E A W R E C K .

L E A R N I N G G O A L S



C h a p t e r 8 - W r e c k D i v i n g

tial hazards associated with wreck diving. This activity is

definitely a specialty, requiring training, special equip-

ment, and experience to ensure enjoyment. You are

about to gain some insight into this exciting and chal-

lenging pursuit, but you must be aware that you will by

no means be qualified to engage in wreck diving activi-

ties beyond those to which you are introduced.

Penetrations, external surveys, salvage, and similar

activities on wrecks require special training.

P O S S I B L E H A Z A R D SIn addition to the possible environmental condi-

tions of currents, limited visibility, and deep water,

other potential problems include silt and hazardous

animals. It is common for wrecks to be covered with a

layer of silt and sediment that has filtered down upon itfor years. The slightest disturbance can raise a cloud

that can immediately reduce visibility to zero. Being

able to move about without disturbing silt is often a

requirement (figure 8-3).

Wrecks are artificial reefs-often the only shelter in

an area-and are havens for life. This is one of the

attractions of wrecks, but it can also present problems

because of potentially hazardous animals that dwell in

F IG U R E 8 - 3 . L E A R N I N G A G O O D P I N N I N G T E C H N I Q U E T H A T A V O I D S

D I S T U R B I N G T H E B O T T O M , W H E T H E R N E A R A R E E F O R

I N S I D E A W R E C K , H E L P S P R E S E R V E T H E E N V I R O N -

M E N T A N D T H E V I S IB I L I T Y .

wrecks. You need to know what creatures could be

harmful, how to identify them, where they are likely to

be encountered, and how to avoid injury from them.

F I G U R E 8 - 2 . B E F O R E Y O U R E M O V E A N Y T H I N G F R O M A W R E C K C O N S I D E R T H E L E G A L A N D E T H I C A L IS S U E O F A R T I F A C T C O L L E C T IN G




Being armed with this knowledge and using some cau-

tion will allow you to enjoy the animals while helping to

prevent injuries.

Since fish and other life is abundant, wrecks arepopular with fishermen, both anglers and commercial

fishers. Expect to encounter fishing line, hooks and even

nets on wrecks. Entanglement in these is possible, but

getting caught is usually not a danger if handled prop-

erly. A sharp knife for cutting line and nets is essential.

The greatest hazards of wreck diving are encoun-

tered when divers enter the interior of sunken vessels. It

is very easy to become disoriented in an unfamiliar

maze of passageways, especially when references are at

unusual angles because of the orientation of the wreck.

Darkness, silt, entanglements, and anxiety compound

the problem. Entrapment is also possible should any

part of the wreck collapse or move while you are inside

or underneath it. There is a great deal you need to know

and be able to do before you can penetrate wrecks

underwater.

Two possible hazards for you to keep in mind for

your introductory, non-penetration external survey dive

are sharp edges and losing your bearings. Deterioration

of metal underwater causes it to become thin, sharp,

and jagged. Serious cuts are possible. Heavy gloves are

mandatory. It is easy to become disoriented on a wreck

unless you follow the procedures that will be outlined.

Pay particular attention to this area during your studies

and during your dive.

E Q U I P M E N TYour wreck diving gear includes all your regular

gear, such as full instrumentation, an extra second stage

on your regulator, a dive knife, and gloves. Having a

dive light does not qualify you to enter a wreck. It takes

additional equipment, training, experience and practice.

Some additional instruments are needed.

Minimally, these include a depth gauge or dive comput-

er and a compass. Note that the compass will not per-

form properly when on or near a metal wreck. In fact,

erratic behavior by a compass can sometimes indicate

that you are close to a wreck for which you are search-

ing. An underwater slate is always useful for recording

observations and for communications.

Wreck diving is often done from a boat. The boat

may anchor directly on the wreck or in some instances a

permanent mooring may be in place. In either circum-

stance, divers can descend directly to the wreck site using

the anchor line as a down-line (figure 8-4). If there is

current present a "trail line" or "current line" shoulddeployed behind the boat to be used by divers who sur-

face down current from the vessel.

FIGURE 8-4. IF YOUR BOAT IS ANCHORED 0N OR NEAR THE WRECK THE ANCHOR LINE MAKES A GOOD DESCENT AND ASCENT LINE FOR THE DIVE




Serious external survey or penetration wreck diving

at the specialty level requires additional specialized

equipment. This gear and its use are covered in the

Wreck Diving Specialty course.

P R O C E D U R E SYour first task is to locate a wreck. For this course,

that is the responsibility of your instructor. Other sources

include commercial dive boats, commercial fishermen,

charts, record searching, and other divers. Finding a

wreck can often be as challenging and rewarding as div-

ing on it. Always be sure the wreck you seek will be with-

in your limits of ability.

When you find a wreck and enjoy diving on it, you

will need to carefully mark your location so you can relo-

cate the wreck for future dives. This can be done by taking

a "fix" as described elsewhere, taking bearings carefully,

and/or using a GPS or other electronic navigation equip-

ment. If you only have a general position, when you

arrive in the vicinity you will want to pinpoint the wreck

as closely as possible. This may be done with the aid of a

depth sounder/finder, a magnetometer (metal detector),

or by dragging a weighted line or grapple in an attempt

to snag the wreck. When your instructor or the boat cap-

tain locates a wreck for your dive, pay attention to the

techniques used so you can better understand them.

Your planning for the dive needs to be more

involved than usual. You should obtain drawings, dia-

grams, or pictures of the wreck so you can familiarize

yourself with it. Note the dimensions, the shallowest and

deepest depths, and the orientation of the wreck with

respect to the bottom and to compass direction for pur-

poses of navigation. Does the wreck parallel the shore-line or run perpendicular to it? Information such as this

can help you locate a wreck and navigate better while

you are diving on it. Find out if the wreck is intact.

Consult the tide tables to determine slack water time.

Find out about potential hazards and prepare yourself to

be able to identify them and cope with them. All of these

steps are necessary in addition to all of the regular ones

of your dive plan.

As mentioned, wreck diving is often done from a

boat. Upon arrival at the vicinity of the wreck, use the

time spent pinpointing its location to evaluate condi-

bility of the current weather pattern to decide whether or

not it is appropriate to dive. Conditions can be further

checked as the boat is being anchored and you set up for

the dive. Watch the anchor as it is lowered to check the

visibility, and watch the trail line float, as it pays to

check out the strength of the current.

Be aware that an anchor line can be chafed or cut

by a wreck if you anchor on one, but this is a common

and reliable way to position a vessel for wreck diving.

However, if you can get on the wreck without anchoringin it, this is preferred, since anchors can severely dam-

age wrecks, spoiling them for future dives.

If diving from a private vessel it is a good idea to

check the anchor and make sure it is secure. The next

step is very important - that of orienting yourself to the

anchor line and to the wreck itself. Which way is the

wreck positioned in relation to the line? What distin-

guishing features of the wreck can be used to help you

recognize the area where the anchor line is located? Use

the techniques to which you were introduced on your

navigation dive. Get a compass bearing so you will be

able to return to the anchor line for your ascent. Pick

out a landmark at the far limit of the visibility and work

your way to it. Upon reaching the landmark, look back

to view what you have traversed from the opposite direc-

tion, then look ahead to the next landmark or feature,

work your way to it and so forth. To return, just proceed

from landmark to landmark in the reverse order. It is

common for wrecks to have a pattern to them. If you

can quickly identify this pattern, it will help quite a bit

with your orientation. You can also see why studyingillustrations of the wreck in advance can be very helpful.

Before beginning your tour of a wreck, check again

for current(s). Remember currents can change in inten-

sity and/or direction during your dive. If the direction of

the current is not in line with the ship's hull and you

can dive along the lee (sheltered) side, explore the shel-

tered portion of the wreck first.

As you proceed along the wreck, move carefully so

tions. Estimate depth, current(s), visibility and the sta-



I V I A U I A d v a n c e d S c u b a D i v e r

F IG U R E 8 5 . S W I M M I N G T H R O U G H A W E L L -L IT , O P E N W H E E L H O U S E

I S N O T C O N S I D E R E D P E N E T R A T I O N W R E C K D I V I N G .

V E N T U R I N G I N T O A R E A S W H E R E Y O U N E E D A D I V E

L IG H T , IN T O I N T E R N A L P A S S A G E W A Y S O R A R E A S

W I T H O N L Y O N E O P E N I N G M U S T B E A V O I D E D U N T I L

P R O P E R L Y T R A I N E D .

little or no silt will be raised. Pull yourself along with

your hands as much as possible. Swim with your fins at

a slight upward angle so their thrust will not stir up

clouds of sediment. Try using a frog or a scissor kick

that moves water from side to side, rather than the usual

flutter kick, which moves water up and down and can

stir things up. Kicking up silt can ruin the visibility for

you and for other divers and can make your return to

the anchor more difficult.

If you should become entangled in fishing line,

simply pulling on the line is not an effective means of

getting free. Monofilament line can be extremely strong

and will stretch quite a bit before it snaps. You may alsopull a fishhook into yourself. Get your buddy's attention

and have him or her untangle you or cut the line. You

can also try reversing direction in order to maneuver the

line in front of you and cut it yourself. Avoid turning as

this usually makes matters worse. The same principles

apply to entanglement in fishnets, although you may

need to remove your scuba unit to free the net. It is easy

to see the need for proficiency in basic skills such as

removing and replacing equipment when wreck diving.

Entering the wreck is definitely inappropriate at the

introductory level. Even partially entering the wreck to

better view the interior can be dangerous because of potential entrapment. Avoid trying to wedge through

narrow openings. If you are so intrigued with the wreck

that you want to explore it internally and in greater

detail, first complete Penetration Wreck Diver Specialty

training. Then you return to the wreck and examine it

more thoroughly with additional training and proper

equipment (figure 8-5).

Check your instruments and the position of your

buddy more frequently than you would on the average

dive. Time and air go by unnoticed when you are inter-

ested in something, and wrecks can be extremely inter-

esting. Your dive planning should include discussion

and agreement on who will lead which portion of the

dive and at what point in time or air pressure you will

turn around and make your way back to the anchor

line.

Upon returning to the anchor line at the end of the

dive, it is wise to again check the anchor to make sure it

can be freed when raised. Your instructor will take care

of this for your introductory dive. Ascending in contact

with the anchor line is recommended so you will surfaceat the boat and not have to swim to it. This is especially

important if you are up current from the vessel when

you reach the surface. Monitor bottom time and remem-

ber to include a precautionary decompression stop at the

end of your dive just as you would on any other dive.

L E G A L A N D E T H I C A L I S S U E S

O F W R E C K D I V I N GPeople are usually interested in taking objects from

wrecks, but this may not be appropriate for a couple of

reasons. In many areas, such as Tobermory in Ontario,

Canada and Truk Lagoon in Micronesia, taking objects

is strictly forbidden because these areas have been estab-

lished as sanctuaries to protect the sites. Viewing com-

pletely intact wrecks such as these is an exhilarating

experience that can be appreciated by all who visit them.




Wrecks in other areas seem to be fair game for sal-

vage, and the temptation to take a porthole or other arti-

fact may be difficult to resist. However, the taking of arti-

facts from wrecks can result in complicated legal prob-lems, and artifacts include just about anything you

might pick up from a wreck. Every country in the world

has laws concerning the salvage of wrecks. You should

always consult local, state, or federal authorities prior to

any salvage attempts, no matter how small or seemingly

inconsequential.

The taking of objects from wrecks is discouraged,

not only because of the legalities involved, but because

you are also removing part of the reason for the attrac-

tion of a wreck site. There are many wrecks that were

once magnificent dive experiences that have lost their

attraction because individuals have irresponsibly

removed all items of interest. A stripped wreck is a disap-

pointment. Controlling the desire to collect objects will

keep you out of legal difficulties, but even more impor-

tantly, will demonstrate your responsibility to the com-

munity of divers who also enjoy visiting wrecks.

Especially wrecks that have all of their intrinsic worth

preserved. The best things to take from a wreck are pho-

tographs.

O V E R V I E W O F A T Y P I C A L

I N T R O D U C T O R Y D I V EYour instructor is likely to assist you with the plan-

ning of the dive by providing a diagram of the wreck to

be visited and, perhaps, by showing pictures of the wreck

itself and the life which lives in and around it. The bet-

ter your orientation to the wreck in advance of the dive,

the safer and more enjoyable your dive will be.The briefing for your dive will be rather thorough.

Organization and coordination is important, and your

cooperation will be required. Pay attention and ask

questions if any clarification of plans or procedures is

required.

You will probably descend as a group by buddy

teams on the anchor line and be guided about the wreck

by your instructor. During your tour, use your dive light

to study colors at close range and to look inside the hull

(from the outside of course). Look around and observe

the marine life. You may want to locate as many types of

aquatic animals as possible and record them on your

slate. Also keep a lookout for hazards. Your instructor

will probably point them out in advance, but be sure to

call them to the attention of your buddy so he or she will

also recognize them and thereby avoid them.

You may observe and point out other possible haz-

ards to the instructor. You may be tested on your aware-

ness of your position relative to the anchor line.

Sometimes the instructor will ask various divers to indi-

cate the direction of the anchor line. This is a good way

to help develop concentration on orientation. Another

question may be for you to indicate how much air you

have left when signaled by the instructor. You might be

expected to indicate this before looking at your gauge.

To have the correct response, you will have to monitor

your gauge frequently. Similar questions can be asked

for depth or elapsed dive time.

Regrouping at the anchor line and ascending on

the line will probably complete the dive. A simulated

decompression or a safety stop will be included.

The debriefing following an introductory wreck dive

is usually quite enthusiastic. Everyone seems to want to

comment and ask questions. This is fine, since a great

deal is learned by discussing everyone's experiences.

Each dive team will be encouraged to share what took

place and what was seen on the dive. Be sure to log the

experience and to mark it as your first wreck dive. You

will know firsthand why wreck diving is one of the most

popular of all diving activities.



C H A P T E R

U n d e r w a t e r

P h o t o g r a p h y





1. Learn what it takes to get started in underwater

photography.

2. Be introduced to the equipment used by under-

water photographers.

3. Understand the basic principles of underwater

photography.

4. Learn some picture taking techniques that will

improve your photographic results.


photographic dive.

I N T R O D U C T I O NUnderwater photography appeals to many, whether

they are interested in transferring already award win-

ning photography skills to an underwater application or

just desire to record their diving memories. It allows you

to share sub-aquatic experiences through images, where

truly, "a picture is worth a thousand words". Taking

photos in "inner space" is also challenging and reward-

ing. Furthermore, this special activity requires and

develops a high degree of proficiency in the fundamen-

tal skills of diving.

The adage, "Take nothing but pictures, leave noth-

ing but bubbles", is becoming more and more appropri-

ate as an ever-increasing number of people are visiting

the underwater world. In addition to all of this, photog-

raphy can be a source of profit to those who develop the

ability to capture images worthy of being published.

Quality underwater pictures are always in demand (fig-

ure 9-1).

This chapter will familiarize you with an exciting,enjoyable pastime so you can determine if you would

like to learn more about it by taking a NAUI Underwater

Photography Specialty course. You can always learn

more about photography, but during the specialty course

you can learn the basics and quickly develop your ability

to consistently capture high quality images on film or

digital format. If any or all of the above aspects of

underwater photography appeal to you, then you will

very much enjoy your introduction to this special inter-

est area of diving.

G E T T I N G S T A R T E DUnder the right conditions-namely clear water-it is

easy to take photos underwater. This can be done with

simple, waterproof snapshot cameras, or excellent pic-

tures can also be obtained quite easily with more expen-

sive amphibious cameras by using highly sensitive film

and the natural light.

When the water isn't clear, it is still possible to

obtain good photographs, but simple cameras usually

do not produce good results, and the point-and-shoot

technique may not be effective. The use of wide-angle

lenses, close-up attachments, artificial lighting

(strobes), and proper picture-taking techniques can pro-

duce good results, however.

D I V E R S A I D R E Q U I R E S G O O D B A S I C D I V I N G S K I L L S

T O B E F U L L Y E N J O Y E D .

F I G U R E 9 - 1 . U N D E R W A T E R P H O T O G R A P H Y A P P E A L S T O M A N Y



C h a p t e r 9 - U n d e r w a t e r P h o t o g r a p h y

S O M E F U N D A M E N T A L SIt helps to compare a camera to your eye to under-

stand photography (figure 9-2). Both are self-contained

and have lenses, irises (called an aperture in a camera),

light recording surfaces, and shutters (the eye uses the

lid as the shutter). If you open your eye momentarily,

light passes through the iris and is focused by the lens of

your eye onto the light-sensitive surface in the rear of

the eye. When less light is available, the iris of your eye

opens wider to allow more light to enter and record the

image. If it is dark, a source of light is needed in order

to supply enough light for vision. The same principles

apply to a camera. The shutter is opened to allow light

to pass through the aperture and be focused onto the

film surface by the lens. The less light present, the wider

the aperture must be opened. At times, a flash must be

used to provide enough light to properly expose the film.

The principle of photography is to register

reflected light rays on film in a controlled and pre-

dictable manner, and the less light there is, the more

challenging the task becomes. As a diver descends intothe water and depth increases, the amount of light

decreases. The light from the surface is absorbed and

diffused and is often insufficient for natural light pho-

tography. The lack of adequate available light often

requires light to be supplied artificially with lights,

strobes or flashes.

Another important reason for using artificial light is

to add color to photographs. You are probably aware

that white light is comprised of various colors. As you

learned in your entry-level scuba course, different colors

are absorbed at different depths as the light passes

through the water. Bright colors such as red and orange

will not be recorded on film unless the water is very

shallow because these colors of the natural light spec-

trum have been absorbed by the water and cannot be

reflected from a red or orange object at depth. By illumi-

nating objects at close range with artificial light, their

colors become visible. Without artificial light, pictures

appear predominantly blue and with minimal contrast.You now know two good reasons for using an artifi-

cial light source underwater, but the use of the light

source requires certain light-handling techniques for

good results. There are almost always particles sus-

pended in water, and if light from your flash unit strikes

these particles straight-on and is reflected from them

back into your camera, the result will be "backscatter,"

or a picture that looks like it was taken in a snowstorm.

The more turbid the water, the greater the problem. Not

stirring up silt is an absolute requirement in order to

obtain acceptable photos, and you will learn how to

minimize backscatter through proper light positioning

techniques such as side-lighting.

When light rays pass from air into water or from

water into air, they bend or "refract." The refraction,

which occurs underwater at the face mask/water inter-

face, causes the familiar magnification of objects. It also

causes them to appear closer than their measured dis-

tance. Understanding and compensating for this phe-

F I G U R E 9 - 2 . A C A M E R A I S D E S I G N E D T O A D M I T A M E A S U R E D A M O U N T O F L I G H T A N D F O C U S I T O N F I L M I N O R D E R T O P R E S E R V E A R E F L E C T E D I M A G E




F E S S I O N A L P H O T O G R A P H E R S .

nomenon is important for photography. The lens on a

camera must be focused, and if you focus it for the actu-

al distance to the subject, your picture may not be sharp

because the apparent distance to the subject is less than

your setting. You must focus on the apparent distance as

perceived by the eye and as would be seen when focusing

through the lens with a single lens reflex camera.

Refraction also makes it harder to accurately point

a strobe or a flash at a subject. You will learn how to

compensate for this in the Picture-taking Techniquessection of this chapter.

E Q U I P M E N TAll types of cameras may be used underwater as

long as they are housed in waterproof, pressure-proof

containers that allow access to the controls. Still cam-

eras, movie cameras, and video cameras are all used

successfully underwater. The majority of underwater

photography is "still" photography, so we will concen-

trate on that area; but the principles and techniques of

underwater photography for still cameras apply to digi-

tal photography, cinematography and underwater video

as well.

The two basic types of underwater cameras are

amphibious cameras and housed cameras. Both are

capable of producing quality pictures (figure 9-3). Theadvantages and disadvantages of each type are presented

in detail in an Underwater Photography Specialty course.

The capability to interchange lenses is a desirable

feature found on many cameras used underwater. By

changing the lenses (the lenses must be changed above

water), the area included in a photograph can be varied,

depending on the type of picture wanted and the diving

conditions. Lenses are classified as close-up, wide angle,

F I G U R E 9 - 3 . C A M E R A S C O M E I N M A N Y D E S I G N S F R O M P O I N T A N D S H O O T D I S P O S A B L E T O S O P H I S T I C A T E D A M P H I B IO U S M O D E L S U S E D B Y P R O -




standard, or telephoto.

A strobe or flash unit has already been identified as

an important item of equipment for the underwater

photographer. Strobe units are much more popular

today than flash units; and, like cameras, are amphibi-

ous or may be enclosed in a housing. The underwater

strobes of today offer many features such as automatic

exposure control and variable power settings. As you

learn more about photography, you will become familiar

with the advantages and application of more sophisticat-

ed strobes.

There are many accessory items for underwater

photography. The accessories may be useful or essential.

Examples include a viewfinder to help frame the subject,trays to hold the camera and strobe bracket, arms to

hold the strobe, meters to measure light levels, attach-

ments for taking close-up pictures, filters and diffusers,

etc. The more you learn about underwater photography,

the better acquainted you will become with the purpose

and use of the various accessories.

All of the components for underwater photography

are typically combined into a "system" to allow for ease

of handling. In underwater camera systems the camera,

strobe, and various accessories are connected together toform a unit which can be handled effectively while div-

ing (figure 9-4).

Be very conscious that the equipment you will be

using is subject to pressure, water, and an otherwise harsh

environment. It requires proper, careful preparation and

care to protect it from the elements it will encounter.

Whether you use a camera by itself in clear, shallow

water or a complete system for more complex applica-

tions, you will need to put film into the camera, unless

it is a digital camera. You can use either color or black-

and-white film, and you have your choice of either

prints or slides. Film is rated according to its sensitivity

to light, and you have some control over the results of

your efforts through the selection of the film rating. You

will learn more about various types of film as you

become better acquainted with photography. Basically,

the higher the sensitivity rating number, or "ISO," of the

film, the less light needed to properly expose the film.

F IG U R E 9 - 4 , U N D E R W A T E R P H O T O G R A P H E R S U S E R A C K S O N

W H I C H T O S E C U R E T H E V A R I O U S S E P A R A T E P I E C E S O F

T H E C A M E R A A N D I T S A C C E S S O R I E S T O M A K E I T

E A S Y T O H A N D L E U N D E R W A T E R .

B A S I C P R I N C I P L E SThe most important consideration in underwater

photography is proper exposure of the film. This is con-

trolled in several ways. You have just read that different

types of films have different sensitivities, so that is one

means of controlling the exposure. Another method to

control exposure is with the camera controls. The size of

the aperture or "f-stop" can be varied to admit more or

less light, and the shutter speed (the length of time the

shutter remains open) can also be varied to affect expo-

sures. During your Underwater Photography Specialty

course you will learn the relationship between f-stop,

shutter speed, and film speed.

Another means of controlling exposure is by use of

artificial lighting. The use of an amphibious strobe canprovide light in closer proximity and in a greater

amount than the available natural light (figure 9-5).

This allows more color to be captured on film and for

sharper images because a smaller aperture can be used.

The relationship between the aperture setting and the

area in front of the camera in which subjects will be

in focus will also be explained in your specialty course.

For now, recognize that there is a limited range of focus




F IG U R E 9 - 6 . V A R Y I N G T H E P O S I T I O N O f T H E C A M E R A C A N P R O -

D U C E D I F F E R E N T E F F E C T S I N T H E F I N I S H E D P H O T O .

for underwater photography and that you will need to

know this range when taking pictures during your

introductory dive.

So far you have learned that there are several ways

to control the amount of light reaching the film. For

your introductory dive you will probably be provided

with a camera system which is set up to produce accept-

able results at a given distance, so all you will need to do

is concentrate on keeping the camera steady and com-

posing a pleasing picture. This leads us to the subject of

composition, the remaining ingredient required for a

good photograph. As with the other topics presented thus

far, there is a great deal to consider regarding the com-

position of a photograph, but we will share just a couple

of basic concepts for your immediate use on your intro-

ductory dive.

As you view a scene to be photographed, imaginethe area seen in the viewfinder as being divided into

three equal parts vertically and horizontally. Rather

than placing the point or points of interest in the exact

center of your picture, try to position them at one of the

four intersecting points in your imaginary grid. This

simple rule will help you achieve much more pleasing

results than that of "bulls-eye" shots typical of begin-

ning photographers.

35mm film format is rectangular, that is, it's longer

than it is high, so remember that the camera can be

rotated 90 degrees to better compose vertical pictures for

long, vertical subjects. It is often a good idea to shoot

F I G U R E 9 - 5 , A S T R O B E IS N E C E S S A R Y T O C A P T U R E A L L O F T H E

C O L O R I N P H O T O S T A K E N D E E P E R T H A N A B O U T

T H R E E M E T E R S .



both horizontal and vertical shots of an exceptional sub-

ject. When you photograph a single diver alone, you will

usually want a vertical shot (figure 9-6).

P I C T U R E - T A K I N G T E C H N I Q U E SWe have already mentioned that the gear must be

properly handled. Your instructor will show you how to

hold and handle the camera system. Remember that

underwater photographic equipment is expensive and

rather delicate, so please, treat it that way. Resist the

temptation to twist or turn things that you don't under-

stand. Don't force any controls that you have been

instructed to use, but for some reason do not work easily.

Rather than force anything, let the instructor examine

the problem and correct it if possible. On most cameras,

it is very important that you not push hard on the shut-

ter-cocking lever when the film reaches the end of the

roll. If you do this, you can tear the film off the reel. This

may make it impossible to unload the camera without

ruining the film. Treat the gear with loving care!

You may not have to hold the strobe or aim it for

the pictures you take on your first photo dive, but if you

do, remember the problems with estimating distance

underwater and point the strobe slightly beyond the

subject in order to get the light onto it. Otherwise, you

may have the light pass in front of the subject as you

point it at the apparent image instead of where the

subject actually is.

To reduce backscatter, hold the strobe away from

the lens of the camera and angle it toward the subject.

The need for this procedure explains why strobes are

usually mounted on arms and at some distance from

the camera.You have a lot to think about when you are trying

to dive and take pictures at the same time. This is one

reason why your diving skills improve - they have to!

You will soon develop the ability to move about without

stirring up silt. You must, or your attempts to capture

good pictures will be frustrated. Your buoyancy control

improves because good buoyancy control is needed to

hover near a subject as you make final adjustments or

wait for that perfect moment. A properly functioning

low-pressure inflation system on your buoyancy com-

pensator is required because it allows reliable one hand

buoyancy control. This is another reason to have yourpersonal equipment regularly inspected and profession-

ally maintained. If you want to sharpen your diving

skills, underwater photography will provide an excellent

incentive for you to quickly become proficient.

Camera movement when the shutter is operated

causes many poor pictures. You should position yourself

for stability, and as you are completing your exhalation,

squeeze the shutter release rather than punching it.

Never hold your breath while taking photos underwater.

While this is a natural tendency for most people, photog-

raphers have suffered lung over-expansion injuries by

accidentally ascending while holding their breath and

trying to take a photo. As describe above, a good method

is to exhale fully as you pose the picture in the viewfind-

er, squeeze the shutter release and inhale very slowly as

you release it.

O V E R V I E W O F A T Y P I C A L

I N T R O D U C T O R Y D I V EYour instructor may provide the photographic sys-

tem for you to use, or you may rent it from your local

NAUI affiliated dive center. In either case, it should be all

set up for your use by a trained and experienced under-

water photographer. This set up includes selecting and

loading the film, assembling any accessory items, and

setting all controls.

As part of the briefing for the dive, your instructor

will show you how to operate the camera system. This

will include such things as how to advance the film andcock the shutter, how to operate the shutter release, and

how to turn on and off the strobe if one is used. Pay

careful attention to these instructions.

It is very likely that a camera will have to be shared

for the introductory dive pictures or that more than one

type of camera system will be used. Your instructor may

give you an opportunity to take pictures with different

types of cameras so you can compare the differences in





their use and in the results. In order to keep track of

who took which pictures with which camera, it is neces-

sary to keep a log of the pictures taken with each cam-

era. Most cameras have a frame counter to show thenumber of exposures taken. An underwater slate usually

accompanies each camera on a photographic dive, and

you should record your name, the subject and the frame

number for every picture you take. This will help identify

which pictures are yours when the film is developed.

Have the instructor recheck all of the camera set-

tings just before entering the water. The camera will be

set for a proper exposure at a specified distance. Just take

all of your pictures at that distance and according to the

directions of your instructor and you should obtain

properly exposed photographs.

Don 't worry about not being allowed to change set-

tings on this first dive. You will have your hands full just

handling the equipment, keeping yourself stable and the

camera still, and applying the principles of composition.

Don't forget the importance buoyancy control and prop-

er breathing.

If you have to hold the strobe and point it at the

subject, don't forget to hold it away from the camera

and angle it toward the subject to avoid back scatter and

beyond the apparent image to allow for refraction.

Remember also to turn the strobe off when you are

through taking pictures. This conserves battery power.

If the water is clear and bright, you may take pic-

tures using available light and a wide angle lens. If the

water is dark and turbid, you may take close-up pictures

during your introductory dive. A good procedure when

sharing a camera in any conditions is for you to search

for a subject for your photos while your buddy is taking

pictures and recording them. Your buddy can do the

same when you are using the camera. The rules of thebuddy system still apply, however, so don't wander away

so far that you lose sight of your buddy.

After the dive, it is always fun to get together to view

the results and share your experiences. Some film can be

processed in a very few minutes right at the dive site.

Many dive charters, especially "live aboards," offer film

processing on board. "One hour" photo labs can also

allow you to see the results quickly. Your instructor may

even be able to process color slides by means of easy-to-

use developing procedures. The sooner you can see the

pictures you have taken, the better. And, it is a lot of fun

to view the results as a group.It is quite probable that you will become instantly

"hooked" on underwater photography as soon as you

produce a good picture. Your NAUI instructor will pro-

vide you with information on NAUI Underwater

Photography specialty courses in the area, as you are

qualified to enroll. Taking pictures underwater is a won-

derful hobby that is challenging, rewarding, and can

even be financially rewarding. We hope you enjoy your

introductory experience and all of the photographic

dives you are bound to make in the future.



C H A P T E R

O t h e r D i v i n g

S p e c i a l t i e s





1. Be introduced to some of the other underwater

activities that are available to divers.

2. Understand the precautions associated with feed-

ing fish.

3. Be introduced to spear fishing and the need for

responsible practices that will preserve the envi-

ronment for those who follow.

4. Be introduced to underwater hunting of shellfish,

lobster and the like.

5. Be introduced to underwater collecting of rocks,

bottles, artifacts and shells.

S O M E T H I N G F O R E V E R Y O N EBy this point in your Advanced Scuba Diver course,

you have probably already selected an underwater activi-

ty you wish to pursue and in which you would like to

become more proficient through training and experi-

ence. Diving allows you to engage in many above water

hobbies underwater. It also offers opportunities not

available to those who are unqualified to visit the under-

water world. No matter what your interests, however, div-

ing has something special to offer you. In addition to

the more popular special interest areas presented

already, there are many other diving specialties. If you

aren't already convinced, you are about to discover that

diving has something for everyone.

Maybe you simply enjoy visiting the world beneath

the waters. There is much to be said for just sightseeing,

exploring, observing and identifying aquatic life. These

underwater pastimes appeal to many (figure 10-1).

Fish, shellfish, and plant identification guides areavailable on waterproof paper and on plastic cards. A

great deal of satisfaction can be achieved by identifying

animals you observe underwater. For many, underwater

life identification is an ideal way to spend diving time.

Generally, it is not a good idea to feed animals

underwater. Although it may be exciting and fun,

remember that these are wild animals that can always

react unpredictably. Also they become habituated to

being fed by divers, and some fish have been known to

become obnoxious and belligerent when divers appear

without food. In some areas, such as Stingray City in

Grand Cayman, where the creatures are fed as a matterof course, excursions to feed them are very popular. If

you want to feed the fish, you should learn how and

where to do it from others with experience.

There is a sense of adventure in diving new loca-

tions. Newness is not reserved for far away places,

though. Unique things are commonly discovered when

diving at well-known sites. Coming across new things

keeps many people excited about diving. Sightseeing

and exploring are special interests just as much as wreck

diving or underwater photography. Some divers are every

bit as excited about observing something new as others

are about taking something new from our waters.

F I G U R E 1 0 - 1 E N C O U N T E R S W I T H A Q U A T I C L IF E C A N B E E X H IL A -

R A T I N G . M A N Y D I V E O P E R A T I O N S O F F ER S U C H

E X C U R S I O N S .



C h a p t e r 1 0 - O t h e r D i v i n g S p e c i a l t i e s

Many divers enjoy hunting for game, and if regula-

tions are followed and conservation is kept in mind,marine life will not be decimated by the underwater

hunter. Nevertheless, when a heavily dived area is

stripped of life by enthusiastic hunters, it may be

years—if ever-before the life returns. It is suggested that

hunters seek remote areas to pursue their interest. The

game will be more plentiful there, the effect will be less

because adequate breeding stock will remain, and the

more popular diving areas will be preserved for all divers

to enjoy.

When underwater hunting is mentioned, people

usually think of spearfishing, although divers hunt for

shellfish as well. Spearfishing was the primary activity in

the early days of diving, and it is still very popular today.

Some divers achieve great satisfaction from spearing

elusive fish in competition, while others are satisfied to

have good, fresh fish for dinner (figure 10-2).

Divers hunt on the bottom for flatfish, such as

flounders and sole, among rocks and plants for rockfish

and bass, and even in the open sea for jacks and tuna-

related fish. Spearfishing for certain species is often pro-

hibited, especially in fresh water. Be sure to familiarize

F IG U R E 1 0 - 2 . W H E R E S P E A R F I S H I N G I S L E G A L IT C A N P R O V I D E

D I V E R S W I T H M A N Y S A T I S F Y IN G D I V E S A N D M E A L S .

F IG U R E 1 0 - 3 . S P E A R G U N S M U S T B E T R E A T E D W I T H T H E S A M E R E S P E C T G I V E N A N Y W E A P O N . A C O U R S E I N S P E A R F I S H I N G W I L L P R O V I D E Y O U

W I T H T H E K N O W L E D G E T O P A R T I C I P A T E S A F E L Y A N D E T H I C A L L Y .

U N D E R W A T E R H U N T I N G




yourself with the local fishing regulations. Obey them to

avoid being fined and also to prevent divers from being

given an unfavorable reputation. Etiquette also requires

that you respect the rights of line fishermen in an area

whether you are spear fishing or not.

With the popularity of ecology and conservation

today, it is important that divers not kill fish indiscrimi-

nately just for the "sport" of it. If you return from a dive

with a sack full of small, easily killed fish, you are likely

to become subject to peer pressure. The ethical modern

underwater hunter chooses the type of fish he wants,

hunts that species exclusively, and either gets a quarry of

respectable size or waits until another day. Spearfishing

is a wonderful sport, but good sense requires that it bedone with the interests of conservation in mind.

In some circles it is felt that spearfishing should be

done only while breath-holding, but others find no

objection to using scuba to allow hunting in deeper

water. The major spearfishing competitions are per-

formed while breath-hold diving.

Spearfishing is done with poles, slings, and guns

(figure 10-3). All of these are dangerous weapons and

must be handled very carefully. No matter what your

philosophy about underwater hunting, if you intend to

engage in spearfishing, be sure to complete a NAUI

Underwater Hunting Specialty course. You will learn not

only techniques that will increase your chances of suc-

cess, but you will also learn important safety procedures.

Divers also hunt for shellfish, including lobsters,

shrimp, crabs, crayfish, abalone, scallops, and clams.

The same principles of conservation stated for spearfish-

ing also apply to the taking of shellfish. Many shellfish

take years to reach an adult size and some are immobile.

When all of the animals are removed from an area, it is

easy to see how that particular species may never befound there again. The idea of fish and game regulations

is that if only a certain number and size of an animal is

taken, there will be enough of them remaining to propa-

gate the species. Taking undersized animals or more

than is allowed disrupts the sustained yield principle.

Shellfish are delicious, and fresh shellfish are the

most delicious. There are people who dive just to get

their own fresh seafood, and it is difficult to beat a good

F I G U R E 1 0 - 4 . T H I S S P I N Y L O B S T E R O B V I O U S L Y E X C E E D S M I N I -

M U M S I Z E L I M I T S . M E A S U R I N G Y O U R C A T C H A N D

O N L Y R E T A I N I N G L E G A L S I Z E S N O T O N L Y A V O I D S

L E G A L D I F F I C U L T I E S B U T P R E S E R V E S T H E Y I E L D O F

C A T C H - A B L E G A M E .

diving.

Divers hunt for lobsters in rocks and in wrecks.

There are three types of lobsters: the New England vari-

ety, which has claws; the Langouste type, which has a

spiny exterior but no claws, and the Shovelnose or

Slipper Lobster. Which tastes better is a controversy, but

the meat of all of them is a delicacy.

Lobsters can be as difficult to catch as they are good

to eat. In some areas, only the gloved hand may be used;

and the lobsters are extremely quick. In other areas, use

of a wooden dowel is permitted. By tapping the lobster

on the side of the tail, you can guide it to a position

where you can reach it. Spearing lobster is illegal in U.S.

waters. Also, be sure the ones you do catch meet the

meal prepared on a boat or a beach after a day of good




minimum size requirement. Bringing home legal-sized

lobsters means more than just good food for a meal; the

lobsters are usually accompanied by a diver who is

proud of the catch! (figure 10-4)

Crabs are not as difficult to catch, but it can still be

enjoyable to hunt for them. Since crabs are capable of

regenerating lost limbs, some divers take just one claw

from a crab. The animal will live as long as it has one

claw with which to feed and defend itself. Check local

fish and game regulations as to the legality of this prac-

tice in your area. It isn't often that you can take a meal

from the ocean and leave one there for another day as

well.

Shrimp, crayfish, and prawns are similar to lobster,but smaller. They are found in abundance in some areas

and during certain seasons. No matter how many you

may encounter, take only what you need so there will be

more of the animals for generations to come.

Abalone are merely giant ocean snails, growing up

to a foot in diameter, but they are extremely tasty and

considered a gourmet food. They are found on rocks in

Pacific waters. Some of the largest abalone in the world

live in the ocean off the Western coast of the United

States. These animals attach themselves to the rocks

with a large, suction foot; and a special tool, called an

"Ab Iron" is required to dislodge them. There are several

types of abalone. All of them are edible, but some species

are more tender and tasty than others. You should learn

how to take abalone if they are found in your area and

you are interested in hunting for them. You will learn

such things as the importance of not cutting an abalone

when you remove it from a rock. If it is undersized and

you put it back, it will die if it is cut because the blood of

these animals does not clot and they will bleed to death.

As with all diving special interests, it is always a goodidea to learn how to do something from instructors

experienced in the activity.

Scallops are bi-valves found on rocks, reefs, wrecks

or any solid structure. Some scallops are free swimmers,

while others are free swimmers in their infancy until

they find a suitable location on which to spend the

remainder of their lives. Attached scallops are visible to

the trained eye because the shell is usually slightly open

until disturbed, and the mantle of the animal inside can

be detected. The slightest disturbance usually causes the

well-camouflaged shell to close, and the animal

becomes almost invisible in its surroundings. A knife or

diver's tool is required to break the animal loose. It is

not uncommon to find scallops in abundance in some

areas, and they make an excellent meal.

Clams are typically found in muddy or sandy bot-

toms in both fresh and salt water. They are well known

for their flavor. Clams may be difficult to locate and

hard to get, depending on the visibility, the bottom com-

position, and the depth to which the animal is buried.

Part of the fun of hunting, however, is in overcoming

the obstacles to get a catch!

C O L L E C T I N GDivers can bring home trophies other than game.

Rocks, bottles, artifacts, shells, algae, and other items

are sought and treasured by divers who love collecting

such items from the realm beneath the waters.

Collecting can be a non-destructive pastime; or the col-

lection of certain things, such as tropical fish and sea

shells, can require conservation practices similar to

those presented for hunting. When you think about tak-

ing something, you should always consider the impact it

will have on the environment and on other divers who

may dive in the same area.

Among the most popular items sought by underwa-

ter collectors are bottles. Not only are they unusual and

a good means to recall memories of diving, they can be

of historical and monetary value. Antique bottles can be

worth hundreds of dollars, so it is easy to see why they

are the objective of many divers. Researching books toidentify specific bottles and document them according to

their era, use, etc., is satisfying and educational.

Many divers find great pleasure in bottle collecting.

In some areas where bottle collecting is popular, you

may find bottles stuck into the bottom upside down. This

means that the bottle has been found by another collec-

tor who has inspected it and found it to be of no particu-

lar value. Tidbits of information such as this can be




F IG U R E 1 0 - 5 . C O L L E C T I N G S H E L L S A N D O T H E R M A T E R I A L IS S O M E T I M E S R E S T R I C T E D . M A K E S U R E Y O U H A V E C H E C K E D B E F O R E Y O U T A K E A N Y

T H I N G F R O M T H E A Q U A T IC E N V I R O N M E N T

learned and shared with other underwater bottle collec-

tors. Collecting is a great way to meet people and make

new friends.

Many divers make the objective of their dive the

finding of artifacts. Indian artifacts and other products

of human workmanship are interesting and can provide

valuable historical information. As artifact-seekingdivers become more zealous in their quest for relics, they

frequently become students of archaeology; and signifi-

cant archaeological contributions have been made by

recreational divers who became serious about their pas-

time of hunting for artifacts. After all, a find that is

brought to the attention of experts and shared with

mankind through science and displayed in a museum is

much more valuable than a find which is hoarded away

by an individual. An artifact that is retained privately is

one which might provide critical information to an

experienced archaeologist, and a similar object maynever be found again. It would be tragic if such a find

were to be kept from making its contribution to our

understanding of the past.

Also keep in mind that artifacts are often protected

by law, so be sure to familiarize yourself with laws and

ordinances before you start out after souvenirs of the

past.

Fossil collecting is an underwater activity that is

gaining in popularity in some areas. Seeking and find-

ing an object which is thousands of years old can be

every bit as challenging and rewarding as any other

form of hunting and collecting, and the diver again has

the opportunity to make a contribution to science. Fossil

finds should be shared with archaeologists just the same

as artifacts. Divers have achieved recognition and

acclaim for sharing fossil finds. With any form of col-

lecting in which you may discover something unique, it

is extremely important that a willingness to contribute

your find for the good of mankind be a prerequisite to

your participation in the activity.

Shell collecting is also very popular (figure 10-5).

Because it can involve taking living animals, it requires

conservation-minded participants. Amateur collectors

are encouraged to seek dead specimens. However, even

dead shells provide homes for other animals who take

over their shells. Proper collecting techniques include

finding an area in which shells of a particular species

are plentiful and then taking only one of them. The tak-

ing of all of the shells located, especially if there is a

scarcity of them, is selfish and unethical. When collect-

ing shells in earnest, traveling to remote areas is recom-

mended because the shelling will be better and because

your effect on the shell community may be less harmful.

Taking close-up pictures of living shells is preferred




to the collecting of shells, whether living or dead. The

animals are actually more beautiful when alive and

extended. The beauty of the shell and the memory of the

dive can be preserved with a photograph, while the ani-mal remains to propagate the species and provide enjoy-

ment in the future. Collecting photographs of shells is

an excellent way to combine two very popular underwa-

ter activities.

A form of underwater collecting that is quite enjoy-

able but less well known than the gathering of shells,

artifacts, and bottles, is accumulation of various types of

algae (aquatic plants). The algae is pressed onto paper

and dried to form attractive displays that are good for

decorations and gifts. There are many types of plants,

and finding them and preserving attractive pressings can

be a source of many years of pleasure. Since algae is

plentiful and since only small samples are needed for

pressings, conservation is not a problem. If you would

like to have a unique, enjoyable hobby, consider algae

collecting.

Some people like to dive to collect living creatures

for aquariums. It can be a great source of enjoyment to

have a little of the underwater world in your home for

continuous enjoyment. Conservation, obedience to laws

and regulations, and ethical practices in the taking of

animals are all required for the diver who pursues this

interest. Nets are often used to catch small fish, but

determined collectors frequently use a suction gun,

called a "slurp gun" to pull small fish from cracks and

crevices without harming them. Education in aquarium

maintenance is mandatory, but this learning process is

usually part of the fun for divers who collect animals for

home aquariums.

Divers will collect just about anything they can

carry, including rocks and coral. No matter what youcollect, always consider your responsibility to the envi-

ronment and to the diving community. If you want to

take coral, for example, be aware that the growth of

coral is extremely slow. With this in mind, you should

seek pieces which have been broken by natural causes

rather than adding to the destruction of the environ-

ment, particularly in areas which are heavily dived.

Enjoy your collecting, but always be able to do so in

good conscience. Note: In Florida and many other

places, the taking of coral, whether dead or alive, is

illegal.

C H O I C E S , C H O I C E SWe told you there were many things to do underwa-

ter and that diving had something special to offer to

everyone, and we haven't even mentioned the excite-

ment of ice diving, cavern diving, cave diving, river div-

ing, etc. Some people like to specialize in just one area,

while others like to become proficient in several or in as

many as they can. What a wonderful situation it is tohave so many exciting and rewarding activities avail-

able.

When you are trained to do what you are interested

in doing, you will have more fun, be safer, and have a

better chance of ensuring success. That's what underwa-

ter specialties are all about.




I n d e x

AAbalone 100,101

Advanced Scuba Diver 6

Air Consumption 16,22,32

Algae Collection 101,103

Anchor Buoy Line 16, 70,82,83,84,85

Aperture 89,91

Aquaplane 64

Aquariums 103

Aquatic Life Studies 62

Archaeology 80,102

Artifacts 102,103

B

Back-up Scuba 51

Backscatter 46

Bearings 16. 28,36, 52,75,83

Bottles 101,103

Bounce Dive 58

Buddy Line 44,46

Buddy System 18,94

Buoyancy Control 20,45, 57,93

C

Cameras 63,88,90,91,93,94

Chemical Light 47

Clams 100,101

Collecting 5,6,62,63,66,101-103

Collecting Equipment 62, 63

Compass 16.28-31,33-37,44,52,62

Composition 66,92,94,101

Contingency Plan 55Coral 103

Crabs 100,101

Currents 13,15,32,35, 71,80,83

DDecompression Bar 58

Decompression Safety Stop 58

Decompression Sickness 50, 52, 53,56, 58

Deep Diving 5,50-59

Deviation 32,34,35

Disorientation 45,46

Distance Estimating 30

Dive Lights 35,41-45,65

Dive Planning 6,12,16-19, 54,84

Dive Tables 51, 54, 58, 59

Diver Propulsion Vehicle 63

Diving Environments 5

Down Line 44,47, 53-59,82

Drift Diving 16

E

Emergency Equipment 53

Emergency Preparedness 54

Entanglement 44, 73,82,84

Entrapment 82,84

Extra Second Stage 51,82

F

F-Stop 91

Fix 36, 37,73,75,83

Fossils 40

Freshwater Diving 21Fresh Water Weighting 21

HHang-off Tank 58

Hazardous Animals 81

Hunting 6,62, 98,99,100,101,102

IInstruments 14, 51, 56, 62,82,84

KKnots 72,75,76

LLegal Aspects 81,84,85,99,100,101

Lift Bag 70-77

Light Signals 45

Limited Visibility Diving 28, 34, 40-47,81

naui advanced scuba diver

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