Although there are not many examples that classified capsizing factors systematically, classification of capsizing factors is very important to take countermeasures to decrease capsizing accidents. In this paper, the scope was narrowed down to capsizing accidents in waves which have a high probability of becoming fatal accidents. Investigation reports of Japan Transportation Safety Board were surveyed and the capsizing factors in waves were extracted and classified. A checklist for analyzing capsizing accidents was proposed and it was applied to the accidents surveyed in this paper. As a result, factors which need countermeasures regardless of ship type and the factor which needs countermeasures specifically for fishing boats were identified. Countermeasures for those factors were also organized in this paper.
