That’s a layout of Japanese ships in 1941, not showing all they had during WWII. They had more submarine aircraft carriers than any other navy, the I-400 class being the largest ever built until the 1960’s by the U.S.A. They could surface, launch planes and then submerge again. I think the U.S.A. sunk a confiscated I-400 sub off Hawaii after the war. Too bad they didn’t save it as a museum piece.