The Imperial Japanese Navy submarines

Imperial Japanese Navy submarines

Imperial Japanese Navy submarines originated with the purchase of five Holland type submarines from the United States in 1904. Japanese submarine forces progressively built up strength and expertise, becoming by the beginning of World War II one of the world's most varied and powerful submarine...

 were the largest submarines of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 and remained the largest ever built until the construction of nuclear ballistic missile submarine

Ballistic missile submarine

A ballistic missile submarine is a submarine equipped to launch ballistic missiles .-Description:Ballistic missile submarines are larger than any other type of submarine, in order to accommodate SLBMs such as the Russian R-29 or the American Trident...

s in the 1960s. They were submarine aircraft carrier

Submarine aircraft carrier

Submarine aircraft carriers are submarines equipped with fixed wing aircraft for observation or attack missions. These submarines saw their most extensive use during World War II, although their operational significance remained rather small...

s able to carry three Aichi M6A

Aichi M6A

The Aichi M6A Seiran was a submarine-launched attack floatplane designed for the Imperial Japanese Navy during World War II...

 Seiran aircraft underwater to their destinations. They were designed to surface, launch the planes then dive again quickly before they were discovered. They also carried torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

es for close-range combat.

The I-400-class was designed with the range to travel anywhere in the world and return.