s it's part in the celebration of the surrender of Japan and the conclusion of WWII, the US submarine, Segundo captured one of Japan's secret weapons, the huge submarine, I-401. On it's fifth war patrol the American Submarine, Segundo, captured the giant Japanese air-craft carrying submarine and escorted it to Tokyo. The Captain and crew were congratulated for "the unique and unprecedented act in submarine warfare of capturing and bringing safely to port a Japanese submarine." (G.C. Crawford, Chief of Staff, Commander Submarine Force, Pacific Fleet).