[skeeter]

The Japanese had at least one giant submarine during WW2 that had two small bombers on board. The sub could surface, they would attach the wings, and then off they flew.

The Japanese completed 3 or 4 I-400 class subs built specifically to bomb the Panama Canal. The IJN was always fixated the biggest...

[Southack]

The S-1, with a fully assembled MS-1 seaplane on deck.

1923
Most major navies have tried to use submarines as aircraft carriers, though never with much success. The S-1, the 105th U.S. submarine, was equipped with an on-deck hangar and the Martin MS-1 seaplane. Wishful thinking: Crew had to disassemble the MS-1 to fit it in the hangar and had to reassemble it before flight, forcing the submarine to remain exposed for too long. In addition, launching and recovery proved virtually impossible in the open ocean.