Submarine Tender Taigei
With new classes of submarines introduced, the capability of the existing Jingei-class submarine tender was soon exceeded. To meet the new demands, the development of a new submarine tender was passed under the 1st Naval Armaments Supplement Program of 1933. Taigei was laid down on April 12, 1933 at the Yokosuka Naval Arsenal and was completed in March 1934. However, due to its complex production process and mechanical problems to the diesel engine, repair and improvement continued. Even after completion, Taigei was damaged by a typhoon and it was not until September 1938 she joined the IJN 1st Fleet. On December 20, 1941, soon after the outbreak of the Pacific War, Taigei was docked at the Yokosuka Naval Arsenal for conversion to an aircraft carrier. The conversion was delayed due to damage by the Doolittle Raid of April 1942. Finally, in November 28, the conversion was completed and Taigei was renamed Ryuho.
Junsen Type J-3 I-8 Submarine
The I-8 submarine was developed under the 2nd Naval Armaments Supplement Program of 1934. Being able to submerge deep as 100 meters, she participated in missions ranging from the attack of Pearl Harbor, Guadalcanal, to the Solomon Islands. She is also known for exchanging strategic materials with Germany under the Tripartite Pact. On 31 March 1945, she was sunk after an encounter with U.S. destroyers.