The I-27 was a Japanese submarine whose keel was laid in 1939, launched in June 1940, and commissioned in the Imperial Japanese Navy in 1942. The length of the ship at the time of launching was 108.7 m, width 9.3 m, and the underwater displacement - 3,650 tons. The maximum surface speed of the I-27 was 23.5 knots on the surface. The main armament was six 533 mm torpedo launchers, and the secondary armament was a single 140 mm gun and two 25 mm Type 96 anti-aircraft guns. The ship also took one Yokosuka E14Y seaplane on board.
The I-27 was an ocean submarine of type B1, which in many design solutions was based on the Kaiden type, especially the KD6 type. However, it differed from its ancestors in size, especially in the underwater and surface displacement, as well as in the immersion depth, which increased to about 100 meters. Type B1 ships were also equipped with seaplanes, which gave them greater possibilities in terms of sea reconnaissance, they were also characterized by a large range and high surface speed. During World War II, the ship I-27 operated mainly in the Indian Ocean, where in the period from June 1942 to February 1944 she successfully fought Allied merchant shipping, drowning, among others, ships such as the "Fort Mumford" and the SS Montanan. The ship was sunk in the course of these operations on February 12, 1944 by the British destroyers HMS Paladin and HMS Petard. Only one person survived from the 100-person I-27 crew.