Diving - Kaisi

Japanese: 海士 - かいし

〘 noun 〙 One of the ranks of the Self-Defense Forces in the Maritime Self-Defense Force. Lower than petty officer. Divided into the ranks of chief naval officer, first, second, and third class naval officer. ※Self-Defense Forces Law (1954), Article 32: "The ranks of the Self-Defense Forces in the Maritime Self-Defense Forces are (abbreviated) chief naval officer, first class naval officer, second class naval officer, and third class naval officer."

Man - Amaotoko [Diving diver]

A fisherman who mainly dives to collect seaweed and shellfish. Although ama was originally a word that did not distinguish between men and women, it is common to refer to female divers as "ama," so the male "ama" is used to refer to female divers specifically.

Source: The Selected Edition of the Japanese Language Dictionary About the Selected Edition of the Japanese Language Dictionary Information

Japanese:

〘名〙海上自衛隊における自衛官の階級の一つ。海曹の下位。海士長、一、二、三等の階級に分かれる。※自衛隊法（1954）三二条「海上自衛隊の自衛官の階級は〈略〉海士長、一等海士、二等海士及び三等海士とする」