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
By 1921, Japan's naval expenditure reached nearly 32% of the national government budget. In 1941, the Imperial Japanese Navy possessed 10 battleships, 10 aircraft carriers, 38 cruisers (heavy and light), 112 destroyers, 65 submarines, and various auxiliary ships.