A case study of measurement of a turning circle of a purse seine training ship

"We have to estimate an action of a school of fish and must surround a school of fish in a short time with American-type bonito-tuna purse sine operation. The net length of a purse seine of the Kakuyo-maru which belongs to the Faculty of Fisheries at Nagasaki University is decided. It is necessary to grasp it for size of the turning circle that corresponds to a speed and a rudder angle, and for necessary time. By means of GPS, we measured a turning circle of the fishery training ship Kakuyo-maru that has Americantype bonito-tuna purse seine operation equipment and can operate with a mono-ship. In result, we were able to measure the size of each turning circle around a right and a left turning at three kinds of speed and rudder angle. The necessary turning times of the Kakuyo-maru differs by speed and rudder angle. However, if rudder angle is more than 15 degrees, the size of turning circle of Kakuyo-maru was able to confirm that, inside the limit of a size of a circle that corresponds to a length of a purse seine net."