Wavelet Analysis for Ship Rolling Motion of Purse Seiners in North Sulawesi, Indonesia

摘要

A study of coastal fishing boats (small purse seiners) was made in North Sulawesi province, Indonesia. The goal of this study is to clarify the rolling motion under fishing operation of the small purse seiners. First of all we examined the boat form of the purse seiners and practical conditions of rolling motion under fishing operations. Based on the data, the characteristics such boat's stability and rolling motion under fishing operation were calculated. The results of the analysis are as follows: the boat types were relatively slim around the hulls, and the boats had the round shape under water, and a boat still used by fishermen had extremely poor stability, and the roll angle increased remarkably in stage when the boat crossed the wave direction with hauling process, and results of Wavelet analysis showed that the purse seiners used in North Sulawesi had the same characteristics of rolling motion, and wavelet coefficients became large in hauling process.