August 1966 COMMERCIAL FISHERIES REVIEW 7 



greater living capacity, and ease of conversion to a variety of types of fishing. Disadvantages 

 lie in the increased cost (estimated at 15 percent) and the added cost and maintenance of a 

 second diesel engine. Close tabs will be kept on operational experiences of this craft by many 

 interested individuals. 



At this point we might ask what has been done to develop devices to decrease roll thus 

 providing a more steady working platform of small fishing vessels already constructed? Con- 

 siderable discussion was devoted to recent work on application of passive free-surface tanks 

 as roll damping devices, but no specific instance of installation or performance data aboard 

 small fishing vessels was given. A rather simple device, commonly used for reducing the 

 roll in vessels of the 30- to 75 -foot range of the Pacific coast of the United States and Canada 

 is the paravane -type stabilizer or "flopper stopper," suspended from outrigger poles. These 

 have been used successfully in vessels to 86 feet long. It is estimated that on the U. S. Pa- 

 cific Coast, nearly all salmon troUers, 90 percent of the albacore tuna trollers, and more 

 than 50 percent of the otter trawlers use these stabilizers. The salmon troUer uses stabiliz- 

 ers 24 hours a day while on the fishing grounds, and the albacore troUer at night while drift- 

 ing. Otter trawlers usually have stabilizers out while trawling. In recent years these devices 

 have been used by most vessels engaged in the royal-red shrimp fishery off Florida's east 

 coast and U. S. shrimp vessels off the northeast coast of South America. Their use permits 

 dragging to be conducted during moderately rough sea conditions. Although one major boat- 

 yard building shrimp vessels includes paravane type stabilizers as standard equipment in all 

 new construction, they are not always used when the vessels fish on the traditional Gulf of 

 Mexico shrimp grounds. The use of these effective and inexpensive aids for roll damping has 

 not yet spread to other fishing areas of the United States. 



ENGINEERING OF INBOARDS AND OUTBOARDS 



Discussions centered on the assumption that the approximate total number of fishing ves- 

 sels is 1.5 million. Of the 70 percent, or about 1 million of those vessels still unmechanized, 

 most are located in Asia, South America, and Africa. Until recently, small indigenous craft 

 were mechanized by light inboard diesel engines ranging from 5 to 40 horsepower. Difficul- 

 ties were encountered with inboard engines because of trouble with the stern gears either 

 through poor design or, in well designed stern gear, poor boatbuilding and mishandling of 

 boats. To avoid these problems, the outboard engine, characterized by being simple, easy to 

 handle, safe, light, and comparatively cheap, was introduced. Continued success of outboards 

 was found to depend a great deal on efficient engine servicing. It was believed by some that 

 the market for outboard engines for small fishing boats is large enough to bring about an en- 

 gine designed specifically for these vessels, but this has not taken place, and much remains 

 to be done in this field. 



NEW MATERIALS FOR VESSELS 



As expected, discussions on materials for fishing vessels centered on Fiberglass Rein- 

 forced Plastic (FRP) and aluminum, which are rather recent newcomers in the construction 

 of fishing vessels. Fiberglass Reinforced Plastic is now a proven hull material providing 

 satisfactory service in commercial, naval, and pleasure craft throughout the world. Since 

 1946 in the United States, it has been used to construct 1 million pleasure craft and 2,000 naval 

 craft. The largest fishing vessel to date of FRP has been a 74 -foot side trawler constructed 

 in South Africa, and the yard which built the vessel is contemplating construction of a 9 6 -foot 

 trawler. Plans call for construction of even larger fishing vessels of FRP in the foreseeable 

 future. 



At the present time, FRP for construction of fishing vessels is manufactured from two 

 components, plastic polyester resin and a reinforcement of glass filaments. Although other 

 plastics such as epoxy resins actually have more desirable physical and weathering charac- 

 teristics, their current high price does not warrant their use for fishing vessels. Reported 

 advantages of FRP over wood and steel are: less weight, excellent impact resistance, re- 

 duced maintenance, ease of repair, and excellent durability. In the United States, the cost of 

 boats made of FRP is competitive with boats made of other materials if 5 or more hulls can 



