Type A2 submarine

The Type A2 submarine was a single class of submarine in the Imperial Japanese Navy during World War II, consisting of one boat, I-12, equipped with an aircraft. The design was similar to the earlier Type A1 submarine, except for the A2's having weaker engines. The boat thus had a lower surfaced speed but a longer range.

Like the Type A1, this submarine was designed to act as a headquarters boat coordinating the operations of submarine squadrons. However, unlike the Type A1, the Type A2 submarine was ineffective in its role and in its only patrol, she sank a freighter and machine gunned the survivors.

USS Ardent (AM-340) and USS Rockford (PF-48) sank a Japanese submarine on 13 November 1944. Postwar research reveals that it was most likely I-12.