Ro-21, originally named Submarine No. 39, was an Imperial Japanese Navy Kaichū-Type submarine of the Kaichū III subclass. She was commissioned in 1922 and operated in the waters of Japan. She was stricken in 1934.
Ro-21, originally named Submarine No. 39, was an Imperial Japanese Navy Kaichū-Type submarine of the Kaichū III subclass. She was commissioned in 1922 and operated in the waters of Japan. She was stricken in 1934. (en)
Ro-21, originally named Submarine No. 39, was an Imperial Japanese Navy Kaichū-Type submarine of the Kaichū III subclass. She was commissioned in 1922 and operated in the waters of Japan. She was stricken in 1934. (en)