notes on longline vessel parameters for pacific …

SPC Fisheries Newsletter #79 — October/December '96

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Longline fishing vessels comein a range of sizes, have differ-ent deck layouts, are made fromeither steel, aluminium, fibre-glass or wood, and are equippedwith a variety of machinery andfishing gear.

Choosing a suitable vessel, ei-ther new or second-hand,presents a plethora of problemsto anyone interested in enteringinto commercial tuna longlinefishing. Costly mistakes can bemade when selecting a vessel.The wrong choice can meanfailure just as the right choicecan increase the chances for asuccessful venture.

Furthermore, the ‘right’ boat inone fishery may not be the mostsuitable boat in another area.Local sea conditions and re-source availability, technicalexpertise of prospective crewmembers, and land-based infra-structure should also be consid-ered as they all have a bearingon suitability of a vessel.

The whole idea of fishing is tomake money. If the cost of avessel is so great that no returncan be made on the investment,then the ‘best’ boat may not bethe most suitable boat.

VESSEL SIZE AND RANGE

Tuna longline trips (for chilledtuna) can last anywhere from oneto three weeks. After three weeksthe first caught fish will start tospoil and will be of little value.

However, for safety purposes avessel should have the capabil-ity to steam for about fourweeks without refuelling. Typi-cally, a vessel has to steam forseveral days to get to the fish-ing grounds, fish for about tensets, and then return to port.

Tuna are highly migratory, soduring any one trip vesselmovements of one or two daysduration may have to be madeto follow the fish, and even af-ter each set smaller movementsare usually made to adjust forcurrents and drift.

In areas where commerciallongline fishing is just startingand the resource is very abun-dant, the above may not neces-sarily be true, but following thefirst few ‘gold rush’ seasons theresource will start to feel the pres-sure of fishing and vessels willhave to range further and fur-ther from home ports to catchfull loads. It may be all right tostart out with a ‘mini’ longliner(15 m [50 ft], or less) but in thelong run it would prove to beunsuitable as it could not adaptto a changing situation.

When considering vessel sizeand other parameters, both suit-ability and versatility need to beconsidered. A versatile vesselcould adapt to other fisherieslike albacore trolling in thesoutheast Pacific, and wouldhave a higher resale value if itwas adaptable to fish in areaswhere the EEZ is bigger andlongline vessels need to have alonger range.

A vessel of 18 to 23 m (60 to75 ft) length overall and of 50 to80 gross registered tonnes(GRT) with a fuel capacity thatwould allow it to steam for fourweeks without refuelling wouldprobably be suitable in mostsituations and versatile enoughto adapt to changes.

A suitable 20 m (66 ft) longlinevessel would be equipped witha main engine of probably notmore than 300 or 400 horse-power (220 to 300 kW) and agenerator with an output ofabout 25 to 30 kW. A vessel sopowered could probably beexpected to burn about 900 li-tres (250 US gallons) of fuel per24 hours of operation.

Therefore it would need to havea fuel capacity of at least 25,000litres or 25 t* (7,000 US gallons).At 10 knots (maximum speednecessary for a longliner) thiswould give it an operating rangeof over 6,000 nautical miles(11,000 km).

These are only the very basicparameters, however, and thereare several more things to con-sider. The next most importantsize parameter of a longlinevessel is fish hold capacity (as-suming beam and depth corre-spond to length, i.e., a 20 m [66foot] vessel with a beam of about5 m [16.5 feet] and a depth ofabout 2.5 m [8.25 feet]).

NOTES ON LONGLINEVESSEL PARAMETERS FOR

PACIFIC ISLAND COUNTRIES

by Stephen Beverly,South Pacific CommissionNoumea, New Caledonia

* Actually one tonne of fuel is not equal to one tonne of tank volume. Fuel is less dense than water so one tonne of fuel mighthave a volume of 1100 litres or so. The specific gravity of fuel depends upon its temperature so this number varies consid-erably. For this report, however, one tonne of fuel will be considered to occupy approximately one tonne of tank volume.


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NOTES ON LONGLINE VESSEL PARAMETERS FOR PACIFIC ISLAND COUNTRIES

If a vessel is capable of makingat least ten sets of 1,500 hooksduring a trip it would expect, onaverage, to catch about 7.5 t ofall species of fish (target speciesand by-catch). This is based ona rough Pacific average CPUEof 0.5 kg/hook (50 kg/100hooks) for tuna longline vessels.

Obviously, fewer fish will becaught on some trips and dur-ing some times of the year, andmore fish will be caught duringother trips, particularly duringthe peak fishing seasons. Asmuch as 15 t of fish could becaught on ten sets during onetrip.

Therefore, for a longline vesselto be both suitable and versatileit should be capable of carryingup to 15 t of chilled tuna and by-catch. The actual size of the fishhold(s) depends largely on thetype of chilling system used.Refrigerated sea water (RSW)systems and slurry systemsneed about 2 t (1 t = 1 m3) ofhold space to chill one tonne offish while ‘ice’ boats need any-where from 3 to 5 t of fish holdspace to chill one tonne of fish(depending on the configura-tion of the fish hold).

Hold space is also needed tostore ample bait for ten sets—about 1.5 to 2 t. If live bait isused then holds need to beadaptable to holding circulatingsea water.

Other less obvious but equallyimportant parameters includefresh water holding capacityand crew complement. A ves-sel that stays at sea for up tofour weeks should be able tohold sufficient fresh water forfour weeks with a reserve.

A typical crew complement fora tuna longliner would be in therange of four to eight people, in-cluding captain (in some opera-

tions the captain serves as engi-neer and fish master). Each manon a fishing vessel would be ex-pected to consume about 25 li-tres (6.5 US gallons) of freshwater per day. For a crew of six(average) this would add up toover 4000 litres, or 4 t (1200 USgallons) for a four-week timeperiod (three weeks plus oneweek’s reserve).

The trend throughout the re-gion is for longline vessels to berequired to take along a scien-tific or compliance observer oncertain trips. Ample berthingand fresh water capacity needsto be considered for such con-tingencies. A suitable and ver-satile long-line vessel shouldhave a crew complement of sixto eight persons and shouldhave a freshwater capacity of atleast 700 litres (200 US gallons)per person. In lieu of a 4 t freshwater tank, a vessel could beoutfitted with a desalinator ca-pable of producing sufficientvolumes of fresh water.

HULL MATERIAL

Although there are a few goodwooden boats in service in thelongline fishery, most vesselsare either steel, fibreglass, oraluminium. Each of these threematerials has its advantages anddisadvantages, and the choice islargely a matter of preference.However, a case can be statedfor each.

Steel vessels are probably themost versatile as they are rela-tively easy to fabricate and re-pair. Steel is also very forgivingto captains who make naviga-tion errors and miss the passthrough the reef. Steel is malle-able and tends to dent or bendrather than crack or break as aresult of collisions. At sea re-pairs and gear adjustments canbe done if a welding machineand oxyacetylene set are part of

the boat’s tools and machinery.Most shipyards are set up towork with steel and steel is rela-tively inexpensive and availablealmost everywhere. On the otherhand, steel rusts and steel boatsneed constant upkeep to pre-vent them from rusting away.

Fibreglass vessels come as fi-bre-glassed plywood, fibreglassreinforced plastic (FRP, GRP),or fibreglassed foam (compos-ites, foam sandwich, etc.) or acombination of these materials.The main advantage to fibre-glass is that it is relatively main-tenance free. There is no chip-ping and painting, no rust, nocorrosion.

Fibreglass is also fairly easy towork with and small repairsand modifications can be doneeasily with materials that areavailable in most places (resin,catalyst, and glass cloth or mat).

Fibreglass is also compatiblewith almost any other mate-rial—steel, aluminium, brass,wood, silicon, rubber, etc.). Themain disadvantages to fibre-glass are that it is flammable,that it cracks, and that it canhave a tendency to absorb wa-ter (osmosis). Osmosis occursparticularly when poor work-manship is involved in layingup the fibreglass or when foam-fibreglass composites are madewithout using pressure.

Under these conditions fibre-glass and composites (fibreglassand foam) can become porous.Water soaks through the fibre-glass and into the foam. Asidefrom that, if a fibreglass vesselcollides with another vessel orwith the reef, major hull dam-age can occur—the hull can beholed quite easily compared tosteel.

The worst case, however, wouldbe a fire on a fibreglass vessel.


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Once resin and foam (in thepresence of fuel oil, hydraulicoil and motor oil) are ignited itis very difficult to put out theflames. Burning resin and poly-urethane foam (as in foamsandwich vessels) give off toxicfumes that can be lethal. Steeland aluminium, on the otherhand, do not burn, althoughthere can be fires on board steelor aluminium vessels.

Aluminium has two main ad-vantages as a hull material.One, it is light weight and thusan aluminium vessel is morefuel efficient than a similar sizedsteel vessel. Two, aluminium,like fibreglass, is relativelymaintenance free.

Aluminium, although it cor-rodes under certain conditions,does not rust. There is no chip-ping or painting to be done, andoften aluminium vessels are notpainted at all above the waterline. An annual wash downwith phosphoric acid is all thatis usually needed.

There are two main disadvan-tages to aluminium vessels, how-ever. One, marine grade alu-minium, unlike steel, is not verymalleable and tends to crackunder extreme stress, as duringan encounter with the reef oranother vessel. Two, aluminiumis difficult to work with and ex-pensive as compared to steel.

A special welding machine isneeded, along with a highly-trained welder, to work withaluminium. Most small ship-yards and slipways do notwork with aluminium so majorrepairs or modifications couldbe very costly.

Aluminium plate is also notavailable in most places. Fur-thermore, aluminium does notget along very well with othermetals. If stainless steel fittings

are used on an aluminium ves-sel, for instance, care must betaken to isolate the two metalsfrom each other with rubber orsilicon. If they are not isolatedand in the presence of sea wa-ter, electrolysis will take placeand the aluminium will corrodeaway and be reduced to a whitepowder.

Lastly, aluminium is a verygood conductor of heat whichmeans that heat can be easilytransferred from machinery tocrew’s quarters or the fish hold.In the tropics, aluminium deckscan get quite hot. This not onlycauses discomfort to the crewbut can affect quality of fishlanded on the deck.

All in all, steel is probably thepreferred material for a longlinevessel unless the vessel will beoperating in a very remote lo-cality with a crew that may notkeep up on regular hull main-tenance. In that case, fibreglass,because of its ease of mainte-nance, would be the preferredhull material. It may be wise onfibreglass vessels to have morethan the necessary minimumnumber of fire fighting devices.

HULL CONFIGURATION

The best hull for longline fish-ing is a deep displacement typehull with a single (hard) chine.Planing or semi-planing hullsor hulls with round or multiplechines should be avoided. Thesetype of vessels are more suitedto coastal (near shore) fisheries,

such as the Australian westcoast cray fishery. It is also goodto have a skeg with a foot plateand pintle bearing for the rud-der rather than shaft struts anda free-standing rudder.

A smooth, uninterrupted linefrom stem to rudder is the idealas there should be few placesfor the mainline to get caughton during hauling of thelongline. Keel coolers and trans-ducers should be on the portside if possible and all zinc an-odes should be mounted so thatthey will not snag the mainline.Bilge keels (roller chocks) shouldbe avoided.

The other main consideration iswhere to put the wheelhouse.Most Asian longline vesselshave stern houses. There areseveral advantages to having astern house. One, the vessel op-erator has a clear view of alldeck operations, including ma-chinery, during hauling. He canclearly see the mainline comingup, and he can monitor all crewactivities as well, including fishhandling and chilling proce-dures.

Two, all fish holds are forwardof the engine room and shafttunnel on a stern-house vessel.This allows more room for holdspace and also reduces the trans-fer of heat from machinery tofish hold. It is easier to make thefish hold water tight if there isno shaft tunnel running throughit. Another advantage to havingthe machinery behind the holds


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is that access to the shaft pack-ing gland (stuffing box) is usu-ally via the engine room, whereit can be easily viewed and re-paired as necessary. On a for-ward-house vessel it is oftenvery difficult to gain access tothe packing gland (to tightenthe gland or add packing) whileat sea fishing.

The shaft tunnel on a forward-house vessel is usually underthe main fish hold and thepacking gland may be buriedunder layers of fish and ice,which would make monitoringand repairing difficult. Thiscould be critical during anemergency.

Lastly, a short tail shaft as on astern-house vessel is less expen-sive than a long shaft as on aforward-house vessel. Often,on forward-house vessels, twoshafts are necessary: an inter-mediate shaft that runs fromthe gear box coupling to justforward of the packing gland;and a tail shaft that exits to thepropeller. Additional bearings(Babbit bearings) are usually fit-ted along the way to supportthis extra weight. A long shaftwould add considerable cost toa vessel as compared to a shortshaft.

There are many forward wheel-house vessels in longline fisher-ies in the Pacific, however. Mostof these started out as some-thing else, like shrimp draggers(prawn trawlers) or net boats, inwhich case a forward housemight be advantageous.

The main advantage for a for-ward house to longline fishingis that the crew is out of theweather. Forward-house ves-sels are also probably betterduring setting operations, as theline can run unobstructed fromreel or baskets to the stern,where baiting takes place.

Many operators of forward-house longline vessels haveadded an outside station on theback deck, usually on the after-bulkhead of the house, wherethe operator can both drive thevessel and control the haulingof the mainline and the removalof branchlines simultaneously.(Hauling is usually done fromthe starboard side so that thevessel operator can have a clearview of the so called ‘dangerzone’ which is the area aroundhis vessel from dead ahead to11 1/4 degrees aft of the beamon the starboard side, or ninepoints off the starboard bow. In-ternational Rules prohibit onevessel from crossing the portbow of another vessel).

FISH HOLD(S) AND CHILLING

SYSTEM

There are several options forfish-hold configuration andchilling systems. Fresh-chilledsashimi-grade tuna can be pro-duced by icing the fish in lay-ers of crushed or flake (or shell)ice, by immersing the fish in aslurry made up of crushed iceand sea water, or by immersingthe fish in refrigerated sea wa-ter (RSW) or a mix of sea waterand fresh water.

The common goal of all thesesystems is to reduce the bodytemperature of the fish to 0°C(32°F) and to keep the fish at ornear this temperature for theduration of the fishing trip.

Each system has its advantagesand disadvantages and thechoice of system has a directbearing on the type of fishhold(s) a vessel would have andthe type of refrigeration ma-chinery necessary to supportthe function of the fish hold(s).The availability of land-basedinfrastructure and market de-mands also play a role in choiceof chilling systems.

Icing fish has several advan-tages over RSW and slurry sys-tems. One, the product is usu-ally better than fish that havebeen chilled in a liquid system.Properly-iced fish do not comeinto contact with other fish orwith the structure of the fishhold. There is little skin damageto iced fish as compared to fishchilled in a liquid.

Damage can occur, however, ifice is not broken up into veryfine pieces or if the starting layerof ice is not of sufficient depth.Iced fish will also keep longerthan fish stored in a liquid sys-tem. Iced fish (tuna) can be keptas long as three weeks and stillbe marketable as export-gradefish. RSW or slurry fish start tobleach out (soak-up water) af-ter one to two weeks.

Furthermore, iced fish requireonly one large fish hold that isusually divided into separatebins with removable boards.RSW and slurry systems re-quire that the vessel have sev-eral fish holds up to a maxi-mum size of about 2 t each. Ifthe holds are too large the fishwill move around, especially inrough weather, and becomedamaged.


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Ice boats, if there is sufficient iceavailable from a shore facility,do not need an on-board refrig-eration system. This is also trueof slurry systems but not true ofRSW systems. Ice boats orslurry boats could have an on-board flake ice machine or theholds could be refrigerated as asupplement to the ice in theholds, but this is not alwaysnecessary. RSW boats, by con-trast, are wholly dependent onon-board machinery (generatorand refrigeration system).

The main advantage that RSWand slurry systems have overicing is that they are less labourintensive. Digging graves in theice is hard work and requires acertain degree of skill and usu-ally has to be done twice foreach day’s catch—once for pre-chilling in a slaughter bin andagain the following day in oneof the main bins in the fish hold.RSW and slurry fish are merelydropped into the tank after clean-ing (bleeding, gilling and gut-ting, bagging). Some vessels usea combination of slurry for pre-chilling and ice for storing fish.

However, this requires that thevessel have at least two tanks,or holds. Multiple tank systemshave the advantage, however,that since there are several tankson the vessel as opposed to onemain fish hold, at least one ofthese tanks can be used for livebait storage; or in the case ofRSW boats, supplementaryfresh water or fuel supply.

One disadvantage to RSW sys-tems is that temperature varia-tions are more likely to occurthan with ice or slurry systems.Another disadvantage to bothRSW and slurry systems is thatfish must be bagged in eitherplastic body bags or muttoncloth (gauze) tubes to preventskin damage. This adds to theoperating expenses.

Notwithstanding the prefer-ences of the captain, fish mas-ter, crew, and fish buyers, theselection of a chilling system ismostly dependent on availableinfrastructure. If there is suffi-cient shore-side ice available,then icing would probably bethe best choice.

Second to this would be a slurrysystem. Neither of these sys-tems depend on on-board ma-chinery (except for pumps to re-move melt water). If there is noshore-side ice available, or if itis too expensive or the supplyis unreliable, then some sort ofon-board refrigeration systemwould be necessary. This couldbe an on-board flake ice ma-chine for icing or for a slurrysystem, or an RSW system.

The main disadvantages to hav-ing on-board refrigeration sys-tems are that initial capital costsare higher and product qualityis wholly dependent on keep-ing on-board machinery opera-tional. Consider the followingscenario:

A company has a choice of fiveice boats supported by a shore-side, five tonne/day flake-icemachine or five RSW boatsand no shore-side ice facility.Which should they choose?The ice boats would requirethat only one piece of refrigera-tion machinery be looked afteras opposed to five pieces of ma-chinery. Furthermore, the icemachine would be on landwhere it could be monitored 24hours a day by one qualifiedtechnician. The choice of RSW

boats would require that thecompany have five qualifiedtechnicians and each of thevery expensive machineswould be subjected to a harshenvironment far away fromparts stores and support infra-structure.

Capital expenditure for five iceboats would be substantiallyless than for five RSW boats—only one fish hold as opposedto several on each vessel, and norefrigeration system needed.However, ice boats with no re-frigeration system are whollydependent on a reliable and af-fordable shore-side ice supply.

With every system of chillingfish it is important to have well-insulated fish holds. Fish holdsshould have at least 5 inches(13 cm) of polyurethane foaminsulation. This may have to bethicker on a bulkhead sharedwith the engine room or a ma-chinery space. Hatches shouldalso be well-insulated and onsome vessels additional plugsare necessary (insulated hatchcover that fits underneath thedeck hatch).

MACHINERY

If a longline vessel is going tobe equipped with some sort ofrefrigeration system there areseveral options to choose from.Ice machines can make eithersea water ice, fresh water ice, orboth. If a fresh water ice ma-chine is selected (fresh water iceis better as it doesn’t freeze thefish) then the vessel would prob-ably also need a water maker,


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or desalinator. It takes a tonneof water to make a tonne of ice.A one tonne per day ice ma-chine would soon use up all ofthe ship’s supply of fresh waterif the vessel did not have adesalinator. Flake ice machinesusually use R-22 refrigerant(Freon).

Sea water in RSW systems canbe cooled by chillers with theevaporators in a remote chillertank away from the fish holdsor it can be cooled by having theevaporators installed in the fishholds either as coils or as plates.Temperature is controlled bythermostatic expansion valves.

Most RSW vessels use R-22 re-frigerant (R-12 refrigerant isbeing phased out world-wideto be replaced by A-134) and R-502 is very expensive. R-717,ammonia, is usually only usedon freezer vessels). The com-pressor for either an ice ma-chine or an RSW system can berun from an electric motor, abelt drive from the main engine,or a hydraulic motor.

The most important piece ofmachinery on a fishing vessel,however, is the main engine.There are a multitude of brands,configurations, horsepower,and types to choose from. Themost important considerationsare initial cost, fuel efficiency,dependability, and availabilityof parts and service.

It is not necessary to have twomain engines on a longliner, noris it necessary to have an enginerated at over 400 horsepower (Ageneral formula to use is threehorsepower for every tonne ofdisplacement—one horsepowerequals approximately 0.75 Kw).

High-powered vessels capableof speeds in excess of 20 knotsare more suited to coastal fish-eries where trip duration is rela-

tively short, i.e., one-to-threedays. Generally speaking, fourstroke six cylinder in-line natu-rally or turbo-aspirated dieselengines are preferable to eightor twelve cylinder superchargedV8 or V12 engines; popularname brand engines and gearboxes with local distributors oragents are more suitable thanexotic brands; dry exhaust sys-tems are more suitable than wetexhaust systems; electric start-ers are more trouble-free thanair or hydraulic starters; andsimple, unsophisticated enginesetups are preferable to ‘hightech’ systems with lots of ‘bellsand whistles’.

Engine start and stop buttonsshould be on the engine, or atleast in the engine room, andnot in the wheelhouse or on theflybridge. This necessitates atleast two trips into the engineroom daily and hopefullywould mean that sump oil lev-els, engine coolant levels, gearbox oil, and bilge water levelswould be checked.

Cable controls (e.g. Morse Ca-bles), for engine throttle andmarine gear shifting are prefer-able to electronic or hydrauliccontrols as they are easier tomaintain or replace. Good enginechoices would be Caterpillar(USA), Gardner (UK), Yanmar(Japan) or Baudouin (France).

Twin Disc is probably the mostpopular marine gear box.

However, there are many othergood brands of marine dieselengines and marine gear boxes.One important consideration isavailability of parts and service.Before an engine and gear boxare selected it would be good totry to identify sources for spareslike fuel and oil filters, injectors,starter motors and alternators,and rebuild kits for pumps andcylinder heads. If these basicitems cannot be accessed then itmay be best to find a more suit-able engine for which parts andservice are readily available.

One very important piece ofmachinery, especially in thetropics, is an engine room ex-haust fan. Ambient engine roomtemperatures can become quitehot during hauling of the long-line gear when the main enginemay be operating at peak RPMand the hydraulic pump oper-ating at peak output.

Exhaust fans should be mountedsomewhere near the exhauststack so that hot air is expelledwhile cool air is being drawn infrom a vent somewhere in theforward end of the engineroom. An on-off switch for theexhaust fan should be mountedin the wheelhouse so the fan canbe switched off in case of fire.

Propellers should be fixed pitch,not variable pitched—and noz-zles are not necessary. Shaftpacking glands should be thesimple, water-cooled-type us-ing Teflon or graphite-typepacking and not oil-filled, al-though grease fittings on shaftglands are probably a good idea.

Another important piece ofmachinery on a longline vesselis the hydraulic system. Themost suitable hydraulic systemis one that is the most depend-


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able. Care should be taken sothat the output of the hydrau-lic pump matches the mini-mum ratings of the hydraulicmotors on the reel and line set-ter (indicated by pressure—inpounds per square inch, PSI;Bars, atmospheres; or Kilo-pascals, 0.01 atmosphere; andcapacity in GPM—gallons perminute or litres per minute).

A typical hydraulic system foroperating a longline reel mightbe rated at 1500 PSI and 10GPM. A hydraulic pump thatruns from a power take off (PTO)on the main engine is probablythe best choice. Electrically-powered hydraulic systems arefine until there are problemswith the generator set. Considerthe following scenario:

A vessel has all of its gear inthe water and then experiencesa generator breakdown. If themain engine is still operationalthen the vessel would be capa-ble of returning to port, even ifthe fishing trip had to be cutshort. If the vessel has a hy-draulic system that runs off ofthe main engine then therewould be no trouble in recov-ering the gear. However, if thehydraulic system is electricallypowered, the entire set of fish-ing gear could be lost as thevessel would not be capable ofhauling the fishing gear.

Ideally, a vessel would have abackup system to cover suchsituations. Additionally, a hy-draulic system that operates alongline system should havesome sort of built in heat ex-changer, either sea-water or keelcooled. Hydraulic line haulersand reels work under a fairlyheavy load for eight to twelvehours during hauling. Hydrau-lic fluid can become quite hotand if it is not cooled, damagecan occur to motor and pumpseals in the system.

WHEELHOUSE ELECTRONICS

The following electronic appli-ances are either basic necessitiesfor longline fishing, or are highlyrecommended. Although it ispossible to operate without allof them, each has a function thatmakes navigation safer or fish-ing more productive or both:

Global Positioning System(GPS) receiver: Gives exact po-sition in latitude and longitudeat intervals of every second—accurate to within about 30 m.A GPS navigator is essential forboth longline fishing and gen-eral navigation.

Colour plotter: this can be sepa-rate from the GPS or can have abuilt-in GPS receiver. A plottergives more detailed informa-tion about the longline set. Theplotter actually draws a picture(plot) of how the line was setand how it was hauled.

A comparison of the two givesthe captain important informa-tion about set and drift (currentdirection and speed) and thepresence of eddies or conver-gences. Events like fish catchescan be entered on the plottereasily by pushing the ‘event’button. Geographical featureslike reefs can also be enteredonto the plotter.

Radar: essential for navigation,especially in areas where thereare abundant reefs or wherethere may be other vessels. Iffishing is done within radarrange of shore, radar can be usedto plot positions of longline set.A thirty-six mile range radarshould be sufficient for a long-line vessel.

Autopilot: autopilot is not es-sential but it is highly recom-mended as during setting it re-lieves one man from steeringthe vessel. Often this man is

needed on deck to help with theset or to bury fish. An autopilotalso gives a much straighter setthan hand-steering would. Someautopilots can also be used dur-ing hauling.

Single side band (SSB), or highfrequency (HF) radio: an HFradio is essential for communi-cation both for general naviga-tion (ship-to-ship and ship-to-shore) and for fishing. Longlinevessels can share catch and fishlocation information with eachother, and can relay catch dataand ETA (estimated time of ar-rival) to agent or manager onshore. With an export fisherydepending on air links to Japanand other international mar-kets, good communications arecritical.

VHF radio: short-range radiocommunication is essential forcommunications with harbourauthorities, agents, and withother vessels in crossing situa-tions to avoid collisions.

Colour sounder: a sounder isimportant for navigation, espe-cially in strange waters whenentering harbours or goingthrough passes in outer reefs.Another function of a sounderthat is important in longlinefishing is its ability to ‘find’ fish.In fact, sounders are often called‘fish finders’. This is not so im-portant for locating schools oftuna but for locating bait thattuna may be feeding on. Somesounders have the capability ofreading the depth of the thermo-cline, thought to be an optimumplace for deeper-water tunas(bigeye). Some sounders areequipped with sea-surface tem-perature sensors and are able todisplay this information graphi-cally on a time line.

Sea surface temperature (SST)monitor: SST data is importantinformation for longline fishing,


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both for tunas and for broadbillswordfish. Fish are often foundon either side of a ‘temperaturebreak’ or an area where tem-perature drops or rises rapidlyin a short distance. Tempera-ture breaks are thought to accu-mulate bait as bait schoolsmove from cooler water intowarmer water or vice-versa.These accumulations of bait at-tract schools of larger fish liketuna or broadbill.

Radio direction finder (RDF)and radio buoys: this is not anessential item as longliners op-erated throughout the world foryears using only lights and col-oured flags on bamboo poles tolocate their lines.

However, using radio buoysand RDFs makes life a lot easierfor the fisherman as he gets torest between setting and haul-ing. Radio buoys are also use-ful when the mainline partsduring hauling. If a buoy can-not be located after a break inthe line then the vessel can al-ways steam to the next radiobuoy.

Usually several radio buoys areattached to the mainline, at in-tervals and at either end. RDFscan also be useful as navigationaids. A Taiyo Model TD-L1100(the most popular model RDF)is capable of tuning to land-basedairport beacon transmitters andto AM radio stations. This infor-mation could tell the captainwhich way to go to return toport in the event all other sys-tems failed. More sophisticatedRDFs allow for eavesdroppingon other vessel’s positions, thusgaining information about loca-tion of other fishing vessels andhopefully fish schools.

Weather fax receiver: weatherinformation is faxed world-wide on a number of frequen-cies. The information comes as

a weather map and is much moredetailed than reports given onHF radio or Inmarsat-C systems.Also available on some frequen-cies are remote-sensing data likesea-surface temperature maps.A weather fax is an essentialitem on any longline vesseloperating in the cyclone belt.

Inmarsat-C: satellite communi-cation between vessels and alsoship-to-shore is possible in a faxmode with Inmarsat-C(Inmarsat-A has voice commu-nication capabilities but is tooexpensive for longline opera-tions). In Hawaii Inmarsat-Csystems are mandatory on alllongline vessels as GPS positiondata of each vessel in the fleetis monitored to insure compli-ance with fisheries regulations.

As an aside, the fleet has beenable to use the Inmarsat-C sys-tem to greatly improve commu-nications with the added benefitthat all communications are se-cure. No one can eavesdrop ona fax transmission so two boatscan share confidential fishinginformation with each other.

Bathythermograph: a bathy-thermograph is an instrumentthat enables the vessel’s crew tomeasure the depth of thethermocline. The thermocline isthat place in the water columnwhere sea water temperaturechanges abruptly and is gener-ally thought to be an optimaldepth for targeting bigeye tu-nas. There are available on themarket, portable-disposablebathythermographs that are af-fordable as well. A bathy-thermograph is probably anoptional instrument.

PC or personal computer: com-puters are becoming more andmore desirable on fishing ves-sels. A PC is necessary forInmarsat-C two-way commu-nications using software like

Galaxy; and software is avail-able with charts for course plot-ting, for monitoring weather,and for getting real-time satel-lite oceanographic data like sea-surface temperatures.

Furuno (Japan) is probably themost popular maker of marineelectronics for longline fishingvessels. However, there are sev-eral other good brands to choosefrom including: Raytheon (USA),JRC (Japan Radio Corporation),Koden (Japan), SEA (StephensEngineering Systems, USA),Icom (Japan), Taiyo (Japan) toname but a few.

FISHING GEAR

There are two main types oflongline gear—traditional, orbasket gear, and compact, ormonofilament gear—with manycombinations and variations inbetween. Basket gear refers tothe original gear as developedby Japanese fishermen decadesago. It derives its name from thefact that the mainline (tarredKuralon or polyvinyl alcohol,and/or tarred Tetron or polyes-ter) was stored in baskets.

Typically traditional gear ishauled by a hydraulically, elec-trically, or mechanically (shaftdriven) line hauler and thebranchlines are coiled by hand.The sections of mainline are ei-ther coiled into some type ofbasket or tub or are tied up intoa bundle, and then stowed in acage or in bins.

Branchlines are usually left con-nected to the mainline and areplaced on top of each successivecoil of mainline. Branchlines aremade from tarred Kuralon, asekiyama or middle wire, aleaded swivel, and a galvanisedtrace, or leader, with hook. Re-finements to this system in-clude the use of electric coilersfor coiling branchlines and hy-


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draulic line coilers (line ar-ranger) for arranging the main-line in a large bin. This type ofsystem is referred to as an ‘auto-matic’ system and is very popu-lar especially with the Okinawanfleet. Branchlines are usuallyseparated from the mainline onautomatic gear, then coiled andstowed in separate baskets.

The line is usually set with a linesetter, or shooter. This gives thecrew better control over depthof the mainline. With traditionalbasket gear the mainline is handthrown over the stern as the ves-sel steams ahead. Depth of set inthis case is variable. The most popu-lar manufacturer of traditionalbasket gear fishing machinery isIzui Iron Works (Japan).

Both traditional basket gearand more modern automaticbasket gear are excellent fishingsystems. However, both basketgear systems have two definitedisadvantages:

•One, the systems are very ex-pensive. New automatic bas-ket gear systems cost, on av-erage, about 25 per cent morethan what a monofilament reelfishing system would cost withequal setting capabilities.

•Two, the systems are very la-bour intensive and require ahigher degree of skill than isrequired for monofilamentsystems. Hand-coiling branch-lines, or even coiling with anautomatic coiler and stowingin baskets, is much more dif-ficult than coiling branchlinesinto a tub as is done with

monofilament systems. Mak-ing up the gear is also muchmore time consuming thanmaking up monofilament gear.Typically it takes a crewmanseveral seasons before he isproficient with basket gear,while monofilament gear can bemastered after only a few trips.

Some vessels, particularly Tai-wanese, use a combination ofthe two systems—monofila-ment mainline is hauled usinga basket-gear-type hauler. Usu-ally on these systems branch-lines are still coiled by hand orwith automatic coilers. Main-line is usually stored in largeplastic or bamboo baskets.

Another system that is some-where in between basket gearand monofilament reel gear isthe Japanese Magu-reel madeby Izui Iron Works. The Magu-reel is a cassette-type monofila-ment system. That is, the main-line is stored on not one, butseveral small reels, or cassettes.

The line is hauled with a hy-draulic line hauler much thesame as is used with basketgear. There is a separate hy-draulic machine called a linewinder that spools the mainlineonto the reels after it has beenpulled aboard by the hauler.The branchlines are removedfrom the mainline and arecoiled either by hand or with anelectric branchline coiler. Magu-reel systems use line setters andfish very well.

However, they are much moreexpensive than single reelmonofilament systems. The onlyadvantage is that the Magu-reelhauler takes up little room ondeck. However, the reels (usu-ally about 10 or 12) need to bestowed somewhere and movedforward and aft on a daily ba-sis. Both the Magu-reel systemsand the automatic basket gear

systems require three pieces ofhydraulic machinery and oneor two electric branchlinecoilers, while basket gear re-quires only one piece of hydrau-lic machinery and monofila-ment reel systems require onlyone or two. Branchline coilerscan be used with monofilamentreel systems but they are not anecessary piece of equipment.

Probably the most popular sys-tem in established and newly-developing Pacific Island long-line fisheries is the compact, ormonofilament longline systemthat uses one large reel to storeand haul the monofilamentmainline.

The system was developed onthe east coast of USA about 15years ago (Lindgren-Pitman)but now there are systems be-ing made in Australia, Europe,and Fiji (Leahy Engineering inAustralia, Bopp in France andSeamech in Fiji). The system iscomposed of a large hydrauli-cally-operated reel made ofsteel or aluminium that cancontain as much as 68 nauticalmiles (125 km) of nylon mono-filament—depending on thediameter of the line and the sizeof the reel. Lindgren-Pitmanhas recently come out with atwo-reel system that is capableof holding over 100 nauticalmiles (185 km) of line.

The line is set from the stern ofthe vessel, usually with the aidof a line setter (shooter) al-though it can be set without ashooter. If the line is set withouta shooter—this is called ‘tow-ing’ the line—then the length ofmainline set is equal to the dis-tance that the vessel travels andthe baited branchlines do notreach into very deep water.

With a shooter the depth of theset can be increased, as thelength of mainline paid out is



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greater than the distance trav-elled by the vessel. Depths of100 fathoms (200 m) or morecan be reached. This is impor-tant when deep-swimming tu-nas (bigeye) are being targeted.As the line is paid out over thestern during setting, baitedbranchlines are attached at in-tervals usually controlled by anaudible signal from a settingtimer.

The number of branchlines setbetween floats is called a ‘bas-ket’ and can vary from 5 or 6 toas many as 30 or 40. Length offloatlines can vary from 5 fath-oms (10 m) to as much as 30fathoms (60 m). A typical oraverage tuna longline set wouldhave floatlines of 15 fathoms(30 m) and 20 branchlines of 5to 6 fathoms (10 to 12 m) in eachbasket. Radio buoys would beattached at either end and atintervals in between.

The monofilament nylon(polyamide) mainline can rangefrom 3.0 mm to 4.5 mm in di-ameter. The branchlines (snoods,gangions) can be made from1.8 mm to 2.1 mm diametermonofilament, 3.0 mm tarredKuralon, 3.0 mm tarred redpolyester, or a combination.

Branchlines can also have swiv-els (barrel, bullet, or leaded) andwire traces. Hooks can be Japantuna hooks with or withoutrings, big-game hooks, or circle(rotating) hooks. Connectionsare usually made with crimpsor swages, but sometimes knotsare used. Connected ends areprotected from chafing withaimata, thimbles, green springs,or plastic tubes.

The line is hauled usually fromthe starboard side of the vesseland stored directly back ontothe reel. Branchlines are re-moved as the line is movingand coiled into branchline bins

or tubs. Floatlines are also de-tached and floats and floatlinesare stowed somewhere on deck.

Monofilament reel systemshave three main advantagesover other longline systems:

•One, the initial cost is substan-tially less than for Japanesebasket gear systems. A com-plete tuna longline system witha monofilament reel for a me-dium-sized vessel (16 to 18 m)would cost about US$ 60,000,while an automatic basket gearor Magu-reel system wouldbe about 25 per cent more.

•Two, monofilament reel sys-tems are simpler than othersystems. It is easier for an op-erator and crew to learn howto master a monofilament sys-tem and it is easier for thecaptain or engineer to main-tain as well. Making up thegear for a monofilament sys-tem is relatively simple andcan be learned in a short time.

•Three, fishing effort can be in-creased, at least as comparedwith most other systems, whenmonofilament systems are used.

Arguably, the automatic basketgear systems, as used by mostOkinawan vessels, are as effi-cient as monofilament systems,but monofilament systems aremarkedly more efficient thantraditional basket gear or Tai-wanese basket gear systems.Cost, simplicity, and efficiencymake monofilament reel sys-tems the best choice for PacificIsland longline fisheries.

VESSEL COSTS

The main idea of commercialtuna longline fishing is to makemoney. If a good return cannotbe made from the initial invest-ment then fishing efforts areprobably a waste of time and

resources (fish and money).Money in the bank, with adjust-ments for inflation, can prob-ably be expected to earn at least5 per cent annually. If a fishingventure does not give investorsa return of at least 5 per cent inthe long run then it is probablynot worth the effort. In order tooptimise the chances of gettinga good return several thingsneed to be considered: there areprobably ceilings on vessel ef-fort, catch, and market perform-ance; expenses—variable, fixed,and marketing—are probablygoing to be greater than ex-pected; and Murphy’s law waswritten by a fisherman: ‘Ifsomething can go wrong, it willgo wrong’. One other thing: fi-nancial projections, especially inthe longline fishing industry,are fiction. Proposed profit-lossscenarios rarely correspondeven remotely to reality afterthe fact. The following oversim-plified financial scenario is of-fered as an example of whatmight be expected:

A medium-sized longline ves-sel with gear cost US$500,000. It makes 1.5 trips permonth of 10 sets each setting1,500 hooks each day of fishing.An average of 5 t of fish arecaught each trip (90 t annu-ally). The market value of thiscatch averages US$ 10,000/t.Annual gross receipts are,therefore, US$ 900,000. Mar-keting expenses in an exportfishery are about 50 per cent ofgross receipts so there is a netback to the company ofUS$ 450,000. Variable costs,or operating expenses (expensesshared by the boat and the crew)are deducted from this net.Variable expenses (fuel, bait,ice, food, etc.) are in the rangeof US$ 10,000/trip or US$180,000 annually (not count-ing salaries and wages). Thisleaves another net of US$270,000. This amount is then



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divided between the boat andthe crew, usually in a 50/50ratio unless the crew are paidon a base wage with bonuses.The crew share is thusUS$ 135,000 (for a crew of sixthis would amount to annualwages of US$ 38,571 for thecaptain and US$ 19,285 foreach of the deckhands). Thebalance is the boat share—US$ 135,000. All fixed costshave to be paid out of thisamount. Fixed costs are basedon mortgage, interest, depre-ciation, hull insurance, main-tenance reserve, license fees,wharf charges, etc. Withoutgoing into all the details, fixedcosts could be expected to be inthe range of 20 per cent of theoriginal investment, or US$100,000 annually. This leaves

a final net back to the operationof US$ 35,000, or 7 per cent.Slightly better than what theoriginal investment wouldmake if the money was just leftin the bank and everyonestayed home.

This oversimplified picturedoes not take into account thespin-off benefits that this boatwould produce: some of themoney earned is foreign exportmoney, so the local economywould benefit and the vesselwould help to create employ-ment both in the fishery and inlocal goods and services. Withmore fine tuning and betterluck the net return might beexpected to grow over time toa higher figure.


If more than US$ 500,000 is in-vested in the vessel initially willthe returns be higher? Probablynot. At higher levels of invest-ment fixed costs become toohigh in relation to gross re-ceipts. A diminishing set of re-turns is the result. On the otherhand, if initial investment canbe kept low, as with the pur-chase of a second-hand vessel,the profit-loss picture mightlook brighter.

In the case of second-hand ves-sels a substantial risk is addedto an already very risky ventureso a high degree of cautionshould be used. Vessels thathave gone bankrupt once shouldprobably be avoided (there areusually good reasons why theygo bankrupt).

Vessels that are offered on ten-der after being seized for illegalactivities can be real bargains,on the other hand. Other waysto improve the profit-loss pic-ture are to seek ‘soft’ loans usu-ally offered through develop-ment banks or internationalassistance organisations; or tomake an outright purchase, inwhich case the vessel could be‘self insured’, saving the com-pany five or six per cent annu-ally of capital costs.

Annual mean Range Median(x US$ 1,000) (x US$ 1,000) (x US$ 1,000)

Revenue 504 58–1,153 481Variable costs 377 40–831 361Fixed costs 100 31–239 98Net return 27 (219)–253 28Add back non-cash depreciation charge 12 3–36 11Cash return 40 (205)–262 38

Average annual Hawaii-based domestic longline vessel economic information

Average annual Hawaii-based domestic longlinevessel characteristics [1 pound = 0.454 kg]

The tables showing average profit-loss from 95 Hawaii-based longline vessels for the year 1993 are extractedfrom: Hamilton, M, R. Curtis & M. Travis. 1996. Cost-Earnings Study of the Hawaii-Based Domestic LonglineFleet. Joint Institute for Marine and Atmospheric Research.

Mean

Vessel length (ft) 69Gross tons 94Total horsepower 457Purchase price (US$ 1,000) 267Additional investment (US$ 1,000) 106Value of electronics (US$ 1,000) 34Number of trips in 1993 10.8Travel days per trip 9.6Fishing days (sets)/trip 10.6Total pounds sold per trip 18,021


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OTHER CONSIDERATIONS

Other things to consider arewhat type of survey is necessaryand what type of registry is re-quired. Depending on local rulesand/or requirements of lendersand insurance companies, avessel may have to be under aparticular survey such as thoseproscribed by American Bu-reau of Shipping (USA), Uni-form Shipping Laws (Australia),or Bureau Veritas (French).

Flag of registry is equally im-portant. After a vessel is pur-chased and imported into acountry it may have to undergoa new survey and be re-flagged.This can be quite expensive,and so should be looked intobeforehand so costly mistakescan be avoided.

Lastly, aside from suitabilityand versatility, simplicity is alsosomething to be sought in alongline fishing vessel. Somewise business manager yearsago came up with this appro-priate acronym to describe auniversal management ap-proach to most situations: the‘KISS Principle’ or ‘Keep It Sim-ple, Stupid’.

The more complicated a long-line vessel and its systems are,the more likely it is to experi-ence costly breakdowns. Anexample of this is hydraulicleader carts for winding in andstowing branchlines and float-lines. The job of pulling in float-ers and floatlines can be doneby hand, and it is on mostlongline vessels.

Some vessels use hydraulically-operated reels, called leadercarts, to wind in branchlines orfloat lines and floats. Hydrau-lic leader carts add a needlesscomplication to an alreadyfairly complex piece of machin-ery, and more problems as well:

one more hydraulic motor tobreak, one more set of hosesand fittings to wear out and bereplaced, one more thing topaint and grease.

This is not to mention the addi-tional initial expense and theroom they take up on deck.There are countless other exam-ples of bits and pieces that couldbe avoided or simplified on afishing vessel including engineroom layout, machinery, decklayout, fishing gear configura-tion and components, pumpingsystems, alarm systems, etc.

THE MASTERFISHERMAN’S

IDEAL LONGLINE VESSEL

The ideal longline vessel forfishing in Pacific Island coun-tries would be 21 m length overall by 6.5 m beam and 3.6 mdepth. It would be made fromsteel and have a single hardchine, a stern wheelhouse, anda raised bow (see appendix Afor general arrangements).

The main engine would be aCaterpillar 3406 with a TwinDisc gearbox, electric starter,keel cooler, and dry exhaust. Itwould have a thirty kW genera-tor set with a name brand likeOnan or Northern lights. Thefuel tank capacity would be25,000 litres and the fresh wa-ter capacity would be 4,000 li-tres. Crew complement wouldbe eight men.

The fish hold would be a single40–50 t hold for icing fish (fif-teen tonne chilled-fish capac-ity). It would be separated intoseveral compartments with alu-minium or wooden bin boards.One bin could serve as a freezerroom for bait storage. Therewould be a hydraulic boom foroffloading fish.

The wheelhouse would beequipped with mostly Furuno

electronics including 36 n.mi.radar, SSB radio, VHF radio,GPS with colour plotter, echosounder with sea surface tem-perature monitor, and aweather facsimile receiver.

It would also have an auto pi-lot and a Taiyo Model TD1100radio direction finder. Optionalgear would be an Inmarsat-Ctransceiver, a PC or personalcomputer (486 with Windows95), and a bathythermograph.

Fishing gear would consist of aLindgren-Pitman Super Spooland LS-4 line setter. Hydraulicsfor the fishing gear would runoff of a belt-driven power-take-off from the main engine andwould run through a heat ex-changer. The LP reel would have50 n.mi. of 3.6 mm monofila-ment mainline. There would be4 branchline tubs each holding440 branchlines (10 m long).

The branchlines would be madefrom tarred red polyester 3.0mm line with 45 g leaded swiv-els and one metre of stainlesssteel wire leader ending in aMustad 3.6 stainless steel tunahook with ring. Other gear wouldinclude at least four radio bu-oys, about one hundred 360 mmplastic floats, about 10 strobelights, gaffs, grapples, spikes, etc.and spare parts for everything.

Last but probably most impor-tant is safety equipment. Theideal vessel would be equippedwith an eight-man life raft, twoor three life rings with strobelights, a 406 EPIRB (emergencyposition indicating radio bea-con), a well stocked medical kit,ample fire extinguishers, emer-gency signal devices (hand-held flares, rocket flares, andsmoke signals), and a separatebattery for the HF radio locatedoutside the engine room. Expi-ration dates on all safety equip-ment would be current.


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21.00 m steel fishing boat

GENERAL ARRANGEMENT II

Scale: as shown

Drawn: GB

Rome, 1983

Main particulars

Length over all 21.00 mLength water line 19.90 mBeam (max) moulded 6.50 mDepth (moulded) 3.60 mDraft at D.W.L. 3.00 mHold capacity 30.00 m3

CSW tank capacity 39.00 m3

Fuel oil 22,500 lFresh water 5,500 lMain engine 300 hp

0 1.00 5.00 m

SB2

Drwg no.Boat no.

1 & 2

General arrangements of an ideal mid-sized steel longline vessel. Adapted from: Eyres, D. J. 1984. Fishingboat designs: 4. Small steel fishing boats. FAO Fish. Tech. Pap. (239): 33p.


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1. Fishing lights2. Navigation lights3. 6.50 m boom, 1000kg SWL4. Search light5. 4.25 m boom6. Anchor roller7. Windlass8. Mainline davit9. Mainline block

10. Fore peak stowage11. Anchor chain stowage12. Accomodation (8 berths)13. Salt water ballast14. Fuel oil tanks15. Fish hold, 30 m3

16. 3 C.S.W. tanks, 13 m3 each17. Engine room18. Gear stowage19. Steering gear and fresh water tanks20. Access to fore peak

21. Wheelhouse22. Concrete ballast23. Chart table24. Deck store25. Inflatable liferaft, 10 man26. Supply vents to engine room27. Line hauler28. Hatch to insulated hold29. Hatches to C.S.W. tanks30. 2 berth cabin31. W.C. and shower32. Galley33. Mess table and seating34. Refrigerator35. Locker36. Hatch to gear store37. Hatch to steering gear38. Sonar space39. Emergency exit from engine room

0 1.00 5.00 m

notes on longline vessel parameters for pacific …

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