Deep off Oahu, divers hunt a vanished World War II supersub.
Off the coast of Oahu, maritime archaeologists descend more than 1,500 feet to investigate a wreck believed to be the I-400, a Japanese submarine aircraft carrier unlike any other of its time. As the evidence comes into focus, the film reveals how this massive secret weapon was built, deployed, and ultimately lost. Sign up to uncover a remarkable chapter of naval innovation and wartime history.
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