Ships in class: 33
The Kaidai type submarine was a type of 1st class submarine operated by the Imperial Japanese Navy (IJN) before and during World War II.
All Kaidai-class submarines originally had a two digit boat name, from I-51 onwards. On 20 May 1942, all Kaidai submarines added a '1' to their name. For example, I-52 became I-152.