The aim of this paper is considering the character of the Sea Scout actibities at prewar Japan, forcusing on the training courses for Sea Scoutmasters which were held in 1928-1937, by examing who got into the training courses, and what they learned there. The training courses were held at mercantile marine schools, various beachs, and the training ship belong to Boy Scout of Nippon. This paper is a part of the research on leader training of the youth (including men and women, boys and girls) organizations at prewar days. Through the leader training, the headquarters of youth organizations taught leaders, who organize the activities practically, knowledge and skills. Moreover, the ideas as the leaders of the youth organizations, and the attitude how they guide members were taught. These could not be taught through magazines or books of the organizations. Previous research has revealed that the Scout troops at prewar days can be divided into two types. Troops based on schools, and troops based on the regions. This could be said to the Sea Scout troops. Not a few teachers at elementary schools participated in the training courses for Sea Scoutmasters. These school teachers tended to have no experience as scout leaders, so that since 1931, participant to the leader training course for Sea Scoutmasters were requested to complete a leader training course for Scoutmasters. There, the participants study skills and knowledge concerning ships and sea, and how they guide Sea Scouts. The interference of naval forces were hardly seen at the training course.
