8/12/2019 CHAPTER 13- 15.docx

1/30

CHAPTER 13 ROUTE PLANNING INFORMATION AND CALCULATION,

CALCULATION ON THE VOYAGE SCHEDULE,CONSTRUCTION OF THE

ROUTE, PLANNED ROUTE CHECKING FOR NAVIGATION

SAFETY,ALTERNATIVE ROUTE, OPTIMIZATION OF ROUTE PLANNING

AND ULTIMATE ROUTE SELECTION

INTRODUCTION TO CHAPTER 13

In the route planning mode, the ECS or ECDIS will allow the entry ofwaypoints as coordinates of latitude and longitude, or the selection of

waypoints by moving a cursor around on the charts. It will allow the creation

and storage of numerous pre-dened routes, which can be combined in

various ways to create comple voyages. !or eample, one might dene a

route from the inner harbor to the outer harbor of a ma"or port, a route for

each of two or more channels to the sea, and several more for open sea

routes to di#erent destinations. $hese can then be combined in di#erent

ways to create comprehensive routes that will comprise entire doc%-to-doc%

voyages. $hey may also be run in reverse for the return trip. &hen selecting

waypoints, ta%e care to leave any aids to navigation mar%ing the route well

to one side of the course. 'any navigational software programs contain

databases listing the location of the aids to navigation in the (nited States

and other countries. $his list should )*$ be used to create routes, because

the accuracy of today+s navigation systems is good enough that to do so

invites a collision with any aid whose actual position is entered as a

&aypoint. lways leave a prudent amount of room between the waypoint

and the aid. Some published routes eist, also a feature of certain software

programs. $he wise navigator will not use these until he has veried the

eact position of each waypoint using the best scale chart.

8/12/2019 CHAPTER 13- 15.docx

2/30

oute creation on an ECDIS can be ddly and frustrating to start with, but

when practiced ma%es the process much uic%er. !or eample, if you were

constructing a /reat Circle route on paper charts it would be fair to say that

this would reuire %nowledge, s%ill and a signicant amount of time0

1owever, constructing a /reat Circle route on ECDIS ta%es seconds as

waypoints are placed at the clic% of a button. 'oreover, there is no need to

rub out your past trac% and re-plan or transfer waypoints from one scale of

chart to another as waypoints are placed on all available charts for its

position. *nce the oute is complete you are presented with all the

information relevant to the route. Enter your E$D

and it will calculate your arrival time based on planned speed or enter your

E$ and it will calculate when you need to depart. If you enter your E$D and

E$ the system can calculate the necessary speed reuired to meet the E$

i.e. S*. Some systems can calculate the e#ect of tide on your route timings

and even calculate (nder 2eel Clearance based upon an entered draught.

*nce the plan is derived it can be saved and used again and again or even

copied to disc and shared amongst a !leet of ships. 1owever, the route

planning function varies between systems with some being easier to use

than others. !urthermore, some systems lac% functionality with regard to

producing

(sing pre-programmed routes from an un%nown source is the same as letting

someone else navigator your vessel. Such a route may pass over shoal

water, under a bridge, or through an area that your own vessel might nd

ha3ardous. lways chec% each waypoint personally. 'any electronic chart

systems will also allow the coupling of the navigation system to the

autopilot. $echnically, it is possible to turn the navigation of the vessel over

to the autopilot almost as soon as the vessel is underway, allowing the

autopilot to ma%e the course changes according to each waypoint. &hile this

may be possible for small craft in most inland, harbor and harbor approach

8/12/2019 CHAPTER 13- 15.docx

3/30

situations, the larger the vessel, the less advisable this practice is, because

autopilots do not ta%e advance and transfer into account. $he large ship

under autopilot control will not anticipate the turn in a channel, and will not

begin the turn until the antenna of the positioning system, presumably /4S

and often located in the stern of the ship, is at the eact waypoint. 5y this

time it is too late, for the turn should li%ely have been started at least two

ship lengths previous. It is perfectly prudent to allow autopilot control of

course changes for vessels in the open sea if the proper parameters for

maimum rudder angle have been set.$he operators can plan and determine

the route of the ship through studying the comprehensive chart data

presented on the ECDIS screen. route can be altered in minute detail, and

the changed route can be saved for later use. )avigation information

including own ship and other ships can be presented in the data cell. &hen

the cursor is placed upon any mar% on the chart screen, the information

about the ob"ects such as buoys, lighthouses, sun%en ships, etc., will also be

shown in the data cell.

Route Checking

ECDIS systems have the ability to chec% the planned route for dangers.

1owever, be careful as the chec% only loo%s within the Cross $rac% Distance

67$D8 or Corridor of the route, so ensure that it is correctly congured to

cover the reuired area. $he wider the

7$D the more alarms will be generated, although this is not a reason to

reduce it below what is reuired. $he chec% loo%s for set parameters which

could be system dened as well as operator dened, depending on the

system. If your system o#ers the ability to congure the search beyond set

parameters, ensure that what you want the system to search for is selected.

lso, when chec%ing the route it is important to ensure that the correct

display setting is selected 6see screenshots below8. In the left hand

screenshot the system is in the Standard display and the route chec% is

8/12/2019 CHAPTER 13- 15.docx

4/30

highlighting a Danger, although it is not shown. In the right hand screenshot

the display has been set to Custom and

Isolated Dangers have been selected for display. $he highlighted symbol is

now displayed 6non-dangerous wrec%8. nother frustration when using ECDIS

systems to chec% a route is that it may highlight the same danger on

multiple occasions without recourse for the operator to clear the specic

danger in one action.

&hen conducting the chec% of the route, the system will only chec% E)Cs

and not )Cs, unless there are manual alarm able constructs within the 7$D.

$he inability of most systems to highlight gaps in E)C coverage for your

route therefore necessitates that a manual chec% on the best scale charts be

conducted for the entire route. )ote that this can be time consuming but

comes highly recommended0 *nce the oute has been chec%ed, additional

information pertinent to the route can be added. $he system can even be

congured to alert the operator of such notices. Considerations at this stage

are how best to display the information so that it can be clearly seen by the

operator. )ote that the font si3e is constrained on many systems

andsymbology is also limited. 4ersonally, I used to favour a 9cloud and

arrow: approach on paper charts to draw attention to supplementary

information, but this is not necessarily available as a symbol in ECDIS. ;ou

must therefore ma%e use of whatever is available and what wor%s for you.

8/12/2019 CHAPTER 13- 15.docx

5/30

Data Display

Route planning with calculation in the table format including:

. recalling the way-points list=

?. planning notes@

A. ad"ustment of a planned route=B.

Some ECDIS route planning tips:

8/12/2019 CHAPTER 13- 15.docx

6/30

>. *rientate the chart to show the beginning and end of the route to get

a 9big handful: !eel for the route.?. Create a blan% canvas by hiding all old routes, constructs etc.A. 5egin with waypoint plotting in the general area of the start and end

of the route.B. Select either humb ine or /reat Circle route etc.. oom in to a more appropriate scale to modify the start and nish

waypoints and 9'assage: waypoints to account for $SS etc.F. F. Ensure that you have adeuate 7$D for the various legs of your

route to ta%e into ccount the nature of the environment and

epected possible deviations, lateral separation from the route and

collision avoidance.G. Chec% ones of Condence 6*C8 or Source Data Diagrams and

amend the route or highlight as necessary.H. Set Safety Depth and Safety Contour values.

8/12/2019 CHAPTER 13- 15.docx

7/30

CHAPTER 14 ROUTE AND VOYAGE MONITORING: CHECKING OF

ROUTE MEASUREMENTS AND CALCULATION, NAVIGATION IN OPEN

SEA, NAVIGATION IN COASTAL AND CONFINED WATERS, CURRENT

AND WINDS EFFECT

INTRODUCTION TO CHAPTER 14

Route monitoring

It is essential that the system is set up correctly prior to eecuting the

route or important information will not be displayed. $his relates to settings

for display, data for the vessel itself and the conguration of larms on

systems that allow it. !or display purposes, the amount of information must

be congured prior to eecuting the route and for this purpose ? types of

display must be available for use with E)Cs= SB> 5ase, Standard and ll

8/12/2019 CHAPTER 13- 15.docx

8/30

*ther. $he 95ase: display 6bottom left screenshot8 provides a minimal

amount of information and represents data that cannot be removed from the

display. s such, the 5ase display does not provide enough information for

safe navigation. $he 9Standard: display 6centre screenshot8 incorporates the

5ase display plus additional features to provide a more appropriate display

for safe navigation 6of note it does not include Soundings8. $he 9ll *ther:

display 6bottom right screenshot8 presents all layers of data and I would

suggest that this provides too much information for e#ective navigation. $his

is because the volume of data shown clutters the display ma%ing it diKcult

to see safety critical information. $herefore, most manufacturers provide an

etra display category, normally called 9Custom: that allows the operator to

congure their display to incorporate information between 5ase and ll

*ther. Some systems also allow the saving of such displays so that the

operator can customise displays for all environments such as 4ilotage,

Coastal, *pen *cean, nchoring etc., selecting them as and when reuired.

1owever, due to the sheer volume of settings and conguration that is

possible, it is recommended that chec%-o# cards be produced to cover all

environments. emember, too much information is as dangerous as too little.

Knowledge and skills should be attained in:

. using loo%-ahead function

?. changing charts and their scales=

A. . reviewing navigational charts=

8/12/2019 CHAPTER 13- 15.docx

9/30

B. vector time selecting=

. predicting the shipLs position for some time interval=

F. changing the pre-planned route 6route modication8=

G. entering independent data for the calculation of wind drift and current

allowance=

H. reacting properly to the alarm=

8/12/2019 CHAPTER 13- 15.docx

10/30

Nav!a"#$ $ #%&$ '&a

*pen-seas navigation using the astrolabe and the compassstarted during

the ge of Discovery in the

8/12/2019 CHAPTER 13- 15.docx

11/30

In this situation no forces are involved and the ship has a pivot point

coinciding with its centre of gravity approimately amidships.

Ma0$! H&a*a

$wo forces now come into play. !irstly, the forward momentum of the ship

and secondly longitudinal resistance to the forward momentum created by

the water ahead of the ship. $hese two forces must ultimately stri%e a

balance and the pivot point moves forward. s a rough guide It can be

assumed that at a steady speed the pivot point will be approimately >BO or

a

8/12/2019 CHAPTER 13- 15.docx

12/30

$he situation is now totally reversed. $he momentum of sternway must

balance longitudinal resistance this time created by the water astern of the

ship. $he pivot point now moves aft and establishes itself approimately

>BO or a

8/12/2019 CHAPTER 13- 15.docx

13/30

Ma0$!H&a*a

&ith the ship ma%ing steady headway however, the pivot point has shifted

to a position Am from the bow. $he forward tug is now wor%ing on a very

poor turning lever of Am

8/12/2019 CHAPTER 13- 15.docx

14/30

Sea rea Selection

oute planning information Construction of oute d"ustment of a planned oute Curve trac% planning

4lanning notes Safety values $ypical errors and actions to ta%e to avoid such errors

Moyage recording and reconstruction of past trac%

is% of over-reliance and complacency on ECDIS

Chec%ing for )avigation safety (ltimate route ,monitored area Mector time Chec%ing measurements larms Current and &ind

Status indication ,indicators and alarms

R#."& P)a$$$!

It should be possible to carry out route planning including both straight

and curved segments.

It should be possible to ad"ust a planned route alphanumerically and

graphically including@

adding waypoints to a route= deleting waypoints from a route= changing the position of a waypoint= It should be possible to plan one or more alternative routes in addition

to the selected route. $he selected route should be clearly distinguishable from the other

routes. n indication is reuired if the mariner plans a route across an own

shipLs safety contour.

n indication should be given if the mariner plans a route closer than auser-specied distance from the boundary of a prohibited area or a

geographic area for which special conditions eist 6see appendi A8.n

indication should also be given if the mariner plans a route closer than

a user-specied distance from a point ob"ect, such as a ed or Poating

aid to navigation or isolated danger.

8/12/2019 CHAPTER 13- 15.docx

15/30

It should be possible for the mariner to specify a cross trac% limit of

deviation from the planned route at which an automatic o#-trac% alarm

should be activated.

8/12/2019 CHAPTER 13- 15.docx

16/30

mar%ing dangerous depths and areas and ehibiting guarding isolines=

mar%ing waypoints with the crossing isolines and critical cross-trac%deviations, as well as by adding, replacing and erasing of waypoints=

ta%ing into consideration safe speed=

chec%ing pre-planned route for navigational safety=generating alarms and warnings=

C#$'"-.("#$ #2 ROUTES

Screen into 9large: or 9planning: screen format. *rientate the chart to show the beginning and end of the route to get a

9big handful:

feel for the route. Create a blan% canvas by hiding all old routes, constructs etc. 5egin with waypoint plotting in the general area of the start and end of

the route. Select either humb ine or /reat Circle route etc.

oom in to a more appropriate scale to modify the start and nish

waypoints and

9massage: waypoints to account for $SS etc. Ensure that you have adeuate 7$D for the various legs of your route

to ta%e intoaccount the nature of the environment and epected possible

deviations, lateral

separation from the route and collision avoidance. Chec% ones of Condence 6*C8 or Source Data Diagrams and amend

the route

or highlight as necessary. Set Safety Depth and Safety Contour values. Conduct a system chec% of the route at an appropriate 7$D to allow for

deviations,

collision avoidance etc. *nce all alarms have been chec%ed and veried, chec% the route in its

entirety on scale by manually scrolling along it. dd relevant additional information and manual corrections.

Double chec% Distance J E$D J E$ and $idal Constraints.

8/12/2019 CHAPTER 13- 15.docx

17/30

4rotect the route as necessary and save a bac%up.

If updates are installed prior to sailing or during the eecution of the

route, ensure

that the route is chec%ed again, as updates may a#ect it

V#a!& -&(#-*$!

ECDIS should store and be able to reproduce certain minimum elements

reuired to reconstruct the navigation and verify the oKcial database used

during the previous hours. $he following data should be recorded at one

minute intervals@

. $o ensure a record of oKcial data used@ E)C source, edition, date, cell

and update history.

In addition, ECDIS should record the complete trac% for the entire voyage,

with time mar%s at intervals not eceeding A hours.

It should not be possible to manipulate or change the recorded

information.

ECDIS should have a capability to preserve the record of the previous

hours and of the voyage trac%.

A*7.'"8&$" #2 a %)a$$&* R#."&

. leg distances?. any speed changesA. wheel over positions for each course alteration, where appropriate

B. turn radius for each course alteration, where appropriate. maimum allowable o# -trac% margins for each leg

C.-v& "-a(0 %)a$$$!

8/12/2019 CHAPTER 13- 15.docx

18/30

. turn radius could show the waypoint over the ground, in shallow waters

and similar navigational ha3ards 4lanning notes

?. $urn radius must provide for the point in which the planned route ischanging from circular into linear not to fall within the circular

navigational route of the net turn. 5etween two circles of two turn

radii there has to be a linear navigational route.A. turn radius should be as large as possible ta%ing into account the

reuirement for maimum speed and reduced number of legsB. $urn radius should be adapted so that in combination with the planned

speed it produces the minimum but acceptable *$ 6from the steering

aspect8.

T%(a) &--#-' a$* a("#$' "# "a0& "# av#* '.( &--#-'

It is important while navigating ship the oKcer of the watch understands

practical procedures to avoid collision guided by masters standing orders.

$hese procedures are only indicative, not ehaustive in nature and one must

always be guided by practices of good seamanship.

8/12/2019 CHAPTER 13- 15.docx

19/30

oKcer.

A. $he **& shall not transfer his duty if he is in doubt whether the

relieving oKcer is physically and mentally capable of carrying out his

duties e#ectively. Instead, he shall advise the 'aster.

B. $he **& shall call the 'aster immediately, if he is in any doubt

regarding navigation, or if the vessel falls into any of the situations

specied in the Qist of Conditions to be reported to 'asterQ

. $he relieving oKcer shall ta%e over the watch after he has conrmed

all items in the Q)avigational &atch $ransfer Chec%listQ

F. $he **& shall maintain a strict and constant loo%-out primarily by

Sight, and use 5inoculars, day and night.

G. $he **& shall observe the compass bearing of all approaching targets

to determine if ris% of collision eists.

H. If the **& is to be relieved, but is engaged in a maneuver or in a M1!

conversation or the li%e, the relief of the oKcer should be deferred until

such action is completed.

8/12/2019 CHAPTER 13- 15.docx

20/30

iv8 void *bstacles and shing nets

.$he **& shall be well aware of use of the 'ain Engine in an

emergency so that he may use the 'ain Engine without hesitation as

reuired.

8/12/2019 CHAPTER 13- 15.docx

21/30

chec% error.

>.$he **& shall chec% the repeaters of the /yro compass 6including

output to DJ4, ECDIS, Course recorder, IS, etc.8 to conrm if

they are synchroni3ed with the master compass.

>>.$he **& shall regularly conrm 4' of the main engine and

presence J absence of alarm generation, and if any abnormality is

discovered, it shall be reported to the Engineer on Duty or the Chief

Engineer.>?.$he Echo sounder recorder should be switched on prior to each

approach to shallow water, to port entry and prior to departure, and

remain in operation while in shallow waters. s a guideline, the **&

shall use the Echo-sounder freuently to measure the depth when less

than B meters and continuously where epected (2C is less than B

mtrs. 1e shall compare the (2C with gures calculated from chart

depths and advise any abnormality.

>A.$he **& shall conrm )avigation ights and other egulation ights,

Shape signals, and &histles are operating properly.

>B.$he **& shall conrm carrying out onboard patrol .

>.In addition to the above, the **& shall comply with the items that

reuire attention for safety of navigation and prevention of

environmental pollution.

>F.!or detailed guidance for )avigational duties, reference shall be made

to the publications R5ridge 4rocedures /uide and R5ridge $eam

'anagement. ll instruments+ recording paper must be annotated

before port arrival Jdeparture and at noon daily, and conrmation done

8/12/2019 CHAPTER 13- 15.docx

22/30

of correct synchroni3ation. )avigational warnings and weather

messages must be read and signed by the **&, and brought to the

notice of the 'aster.

>G.During pilotage, the **& shall continue monitoring the vessel+s

position, %eep loo%out, in the same way as if no 4ilot is on board and

advise 'aster of any abnormality.

>H.$he **& shall enter in the 5ell boo%, the time of 1anding over the

Rcon of vessel to 'aster and the time of ta%ing over Rcon from him.

V#a!& -&(#-*$! a$* -&(#$'"-.("#$ #2 %a'" "-a(0

ECDIS should store and be able to reproduce certain minimum elements

reuired to reconstruct the navigation and verify the oKcial database used

during the previous hours.

T& 2#))#$! *a"a '#.)* 6& -&(#-*&* a" #$& 8$."& $"&-va)':

. $o ensure a record of oKcial data used@ E)C source, edition, date, cell

and update history.?. In addition, ECDIS should record the complete trac% for the entire

voyage, with time mar%s atA. Intervals not eceeding A hours.B. It should not be possible to manipulate or change the recorded

information.. ECDIS should have a capability to preserve the record of the previous

hours and of the voyage trac%.F.

R'0 #2 #v&-5-&)a$(& a$* (#8%)a(&$( #$ ECDIS

ECDIS is becoming mandatory across the shipping sector for safer

navigation, but are operators ready for itT $wo ECDIS instructors shed some

light on the industryLs familiarity with the technology 6or lac% thereof8, and

o#er tips for a smooth transition from paper-based to electronic

8/12/2019 CHAPTER 13- 15.docx

23/30

navigation.$he shipping industryLs transition from time-honored paper

navigation charts to digital navigation systems has now been underway for

long enough that has increasingly come to be seen as the new norm. $he

shift was heavily prompted by a >H ruling by the International 'aritime

*rgani3ation 6I'*8 ma%ing the Electronic Chart Display and Information

System 6ECDIS8 a mandatory technology for an epanding range of

commercial ships under the International Convention for the Safety of ife at

Sea 6S*S8. $he reuirementLs rst deadline in Uuly > made ECDIS

compulsory for new build passenger ships, tan%ers and dry cargo ships of at

least Bgt, ?,gt and

8/12/2019 CHAPTER 13- 15.docx

24/30

C&(0$! 2#- Nav!a"#$ 'a2&"

&henever the navigational situation demands more resources than are

immediately available to the navigator, a dangerous condition eists. $his

can be dealt with in two ways. !irst, the navigator can call up additionalresources, such as by adding a bow loo%out or an additional watch ofcer.

Second, he can lower the navigational demands to the point where his

available resources are able to cope, perhaps by reducing speed, changing

course, heaving to, or anchoringIndicated unrestricted ability, weather clear,

little or no trafc, and all systems operating normally. In this condition,

depending on the si3e and type of vessel and its mission, often a single

licensed person can handle the bridge watch. pplies to situations where

visibility is somewhat restricted, and maneuverability is constrained by

hydrography and other trafc. $his condition may reuire additional

navigational resources, such as a loo%out, helmsman, or another licensed

watch ofcer. Is the most serious, occurring when visibility is poor,

maneuvering is tightly constrained 6as in channels and inner harbors8, and

trafc is heavy.

U)"8a"& -#."&, 8#$"#-&* a-&a

. Increase cooperation and communication among agencies and

organi3ations.?. Enhance long-term support to ensure continuity of sampling.A. 4rovide opportunity for identication and rectication of data gaps.B. llow more timely access to standardi3ed data by all users.. Integrate information for eKcient analysis, synthesis and reporting.F. 4ermit evaluation of large-scale spatial and temporal patterns.G. !acilitate periodic review of ability of monitoring to achieve goals.

H. Epedite lin%ages to other relevant programs.

8/12/2019 CHAPTER 13- 15.docx

25/30

8/12/2019 CHAPTER 13- 15.docx

26/30

eact position at any given time, the internal electronics trac%s that

position in time and calculates shipLs speed.?. Current position accuracy of the /4S system is about meters

with most standard receivers and can be as good as < meter or less

with special ground based repeaters. $he /4S networ% is operated and

maintained by the (S )avy and ir !orce, with the rst of these

satellites sent into orbit in

8/12/2019 CHAPTER 13- 15.docx

27/30

. $o chec% the shipLs position at regular intervals. )ormally, full anchor

watches are %ept even if cargo is being wor%ed while at anchor, this

may be a problem but dec% and bridge have both to be watched.?. Ensure the lightsJsignals are correctly ehibited= usually a M1! watch

will have to be %ept and if youLve been away from the bridge for a time

chec% with the shore station that they have not been calling the ship.A. $ry and get the other ship on the M1! or Pash them with the ldis lamp

if it tries to anchor too close or starts to drag.B. $ry to get a position on the chart and note the shipLs heading at the

moment of letting go the anchor W that way the swinging circle can

best be wor%ed out on the chart. If the scale of the chart is good

enough, it gives a circle within which the ship should remain and is

handy when weighing anchor in a crowded anchorage

A)a-8'

. ma"or functions. In case of a failure, the test should display information

to indicate which module is at fault.?. -ECDIS should provide a suitable alarm or indication of system

malfunction.

A.

C.--&$" a$* W$*

hours prior to sailing, and the process of surveillance

begins. Surveillance is a continuous process, maintained until the ship

8/12/2019 CHAPTER 13- 15.docx

28/30

arrives at its destination. Initial route recommendations are a

composite representation of eperience, climatology, weather and sea

state forecasts, the vessel+s mission and operational concerns, and the

vessel+s seagoing characteristics. planning route provides a best

estimate of a realistic route for a specic transit period. Such routes

are provided when estimated dates of departure 6EDD+s8 are given to

the routing agency well in advance of departure, usually a wee% to

several months. ong range planning routes are based more on

seasonal and climatological epectations than the current weather

situation. &hile planning routes are an attempt to ma%e etended

range 6more than a wee%8 or long range 6more than a month8

forecasts, these recommendations are li%ely to be revised near the

time of departure to rePect the current weather pattern.>. n initial route recommendation is more closely related to the current

weather patterns by using the latest dynamic forecasts than are the

planning route recommendations. $hese, too, are sub"ect to revision

prior to sailing, if weather and sea conditions warrant.?. d"ustment of departure time is a recommendation for delay in

departure, or early departure if feasible, and is intended to avoid or

signicantly reduce the adverse weather and seas forecast on the rst

portion of the route, if sailing on the original EDD. $he initial route is

not revised, only theA. $iming of the ship+s transit through an area with currently unfavorable

weather conditions. d"usting the departure time is an e#ective

method of avoiding a potentiallyB. 1a3ardous situation where there is no optimum route for sailing at the

originally scheduled time. goJno go recommendation may be made

to vessels engaged in special missions such as speed record attempts

or heavy-lift voyages.. diversion is an underway ad"ustment in trac% and is intended to

avoid or limit the e#ect of adverse weather conditions forecast to be

encountered along the ship+s current trac%, or to ta%e advantage of

8/12/2019 CHAPTER 13- 15.docx

29/30

favorable conditions along another route. Ship+s speed is epected to

be reduced by the encounter with the heavy weather. In most cases

the distance to destination is increased in attempting to avoid the

adverse weather, but this is partially overcome by being able to

maintain a nearly normal S*.F. d"ustment of S* is a recommendation for slowing or increasing the

ship+s speed as much as practicable, in an attempt to avoid an adverse

weather situation by ad"usting the timing of the encounter. $his is also

an e#ective means of maintaining maimum ship operating eKciency,

while not diverting from the present ship+s trac%. 5y ad"usting the S*,

a ma"or weather system can sometimes be avoided with no increase in

distance. $he development of fast ships 6S* greater than ? %nots8gives the ship routing agency the potential to Rma%e the ship+s

weather by ad"usting the ship+s speed and trac% for encounter with

favorable weather conditions.

S"a".' $*(a"#$, $*(a"#-' a$* a)a-8'

. s per I'* performance standards, the euipment should include a

function, where the user can select a safety contour from the depth

contours available on the Electronic )avigation Chart 6E)C8. A,

/$ general cargo ship ad"usted its E$ to arrive at the pilot station

earlier than planned in order to meet a high tide. $he vessel

subseuently grounded on a sandban%.?. $he passage plan was amended when the ECDIS was displaying the

E)C at a scale of

8/12/2019 CHAPTER 13- 15.docx

30/30

would pass a starboard hand lateral buoy on the port side whilst

following the direction of buoyage was not investigated further.A. 1ad this been chec%ed, it would have been evident that the amended

passage plan too% the vessel over a sandban% with charted depths

considerably less than the vesselLs draft. 1owever this was not

obvious to the dec% oKcer who amended the passage plan, or to the

bridge oKcer on watch at the time of the grounding. $he safety

contour function on the vesselLs ECDIS was tted with a watch vector

function whereby a time and angle for the predicted movement of the

vessel needed to be set in order to trigger the safety contour alarm.

lthough the safety contour had been set at ?m, the alarm did not function

as the watch vector had not been activated by the bridge team. It was foundthat the 'aster and dec% oKcers had received no formal ECDIS training.

$hey failed to recogni3e the signicance of the safety contour and did not

%now how to set a watch vector ahead of the vessel. $hey were also unaware

of the need to chec% the ECDIS for violations of user dened limiting

parameters 6such as the safety contour8 when ad"usting the passage plan.