The Japanese built four I class subs during
WWII. I class subs still at sea surrendered to American forces
after we bombed Hiroshima and Nagasaki, but this one sunk.
Members of the Hawaii Undersea Research Laboratory located I-401
off Oahu during test dives.
WWII-era
Japanese sub found near Hawaii (hat tip to Boots and Sabers'
Japanese Sub Found off Hawaii).
These were the largest submarines before the nuclear powered
ballistic missile submarines of the 1960s.
The H.I.J.M.S.
I-400 Submarine-Aircraft Carrier says that they had a cruising
range of 37,500 miles, one and one-half times around the globe.
More notably, each member of the I-400 class was
allotted three Aichi M6A1Seiran torpedo bombers--one-off
floatplanes with an 1,800 pound payload prepped for a quick lift
from the boat's bulging hanger to its short flight deck where an
85-foot pneumatic catapult readied them for lift-off A folding deck
crane was provided for retrieval in case anyone came back home in
one piece. I-400 was unusually stable for a submarine of her era
thanks to a split hull design that reduced surface
roll.