Prior to, and during the Pacific War, the Japanese Navy requisitioned many merchant ships from their owners for conversion to auxiliary warships. The types of ships taken over by the IJN varied from sleek passenger liners to tug boats. They were converted to meet pressing military needs for troop transports, fleet oilers, aircraft transports, submarine depot ships, armed merchant cruisers, seaplane tenders, repair ships, minelayers, netlayers and many other wartime uses.
Coverage of all types vessels is impractical, but this page will cover the movements of some of the IJN's regular and auxiliary seaplane and submarine tenders, armed merchant cruisers, coast defense vessels, patrol boats, minelayers, subchasers, minesweepers, repair ships, salvage and repair tugs and hospital ships.
