Submarines of the Imperial Japanese Navy
The ("I-15"-class) submarines (, , , , , , , , , , , , , , , , , , , ) were the most numerous type of submarines of the Imperial Japanese Navy during World War II. In total 20 were made, starting with "I-15", the class ship. These were fast, very long ranged, and carried a single Yokosuka E14Y seaplane, located in a hangar in front of the conning tower, launched by a catapult.
Imperial Japanese Navy
During the Russo-Japanese war, Japan also made frantic efforts to develop and construct a fleet of submarines. Submarines had only recently become operational military engines, and were considered to be special weapons of considerable potential. Naval losses for the Japanese Navy during the war amounted to two battleships, four cruisers, one armored cruiser, seven destroyers, and at least 10 torpedo boats; the majority of them were lost due to hitting Russian mines.