Study of Tuna Clippers on their Fishing Abilities with Classifying Tonnage

After this world war, tuna clippers in Japan have become a tendency of their larger size and enigne power in the type qualified and then they have operated in the Pacific, Atlantic and Indian Ocean mainly. Owing to the special characteristics of the long line fishing, whether the size of ship is large or small, the operational progress has to be in the same method. And then it will be said that all of them in larger types are not used to be more efficiency. Various kinds of method are taken in order to supply these losses widely. From acknowledgement above mentioned, the author has analized the data of 80 tuna clippers from view points of fishing ability and economical matters with classification of the tonnage.