Japan's Forgotten Giant Submarine Discovered After 70 Years

Japan built aircraft-launching submarines to destroy the Panama Canal. And in 1946, the United States Navy deliberately sank these subs, the most advanced ever built — before the Soviet Union could see them. This is the story of the I-400 class, Japan's secret submarine aircraft carrier, and the wreck that was hidden on the ocean floor for nearly 70 years. The I-400 and I-401 were unlike anything ever built. At 122 meters long, they were the largest submarines in the world. Each carried three Aichi M6A Seiran bombers in a pressurized hangar, capable of launching aircraft to strike targets thousands of miles away — then vanishing beneath the surface. They were designed to bomb the Panama Canal, cut America's supply lines, and end the war on Japan's terms. They never fired a single shot. When Japan surrendered in August 1945, the I-401 was en route to attack the American fleet at Ulithi Atoll. Its commanding officer, Lieutenant Commander Nobukiyo Nambu, ordered the aircraft thrown overboard and surrendered to the USS Segundo. The US Navy brought the I-400 class to Pearl Harbor for inspection — then quietly scuttled every one of them before Soviet inspectors could arrive. In 2013, the Hawaii Undersea Research Laboratory found the I-401 on the ocean floor off Oahu, at 700 meters depth. This is what they found. Video Sources: US National Archives... @USNationalArchives Exploration Vessel Nautilus...@EVNautilus University of Hawaii... @UHF CNN...@CNN Become a History X member to support this channel and get access to perks:    / @historyx   Chapters: 0:00 — The Wreck 0:42 — The Technology: A Submarine That Could Launch Aircraft 2:08 — The Mission: Bombing America 4:48 — The Final Order: Ulithi Atoll 7:23 — America Buries the Secret 9:19 — The Discovery: 2013 10:03 — Inside the I-401 Wreck 10:51 — What It Means COPYRIGHT DISCLAIMER UNDER SECTION 107 OF THE COPYRIGHT ACT OF 1976, ALLOWANCE IS MADE FOR “FAIR USE” FOR PURPOSES SUCH AS CRITICISM, COMMENT, NEWS REPORTING, TEACHING, SCHOLARSHIP, EDUCATION AND RESEARCH. FAIR USE IS A USE PERMITTED BY COPYRIGHT STATUTE THAT MIGHT OTHERWISE BE INFRINGING. Screen captures and motion clips used in this video are protected by the Fair Use Law, section 107 used for commentary, criticism, news reporting or education for transformative use. https://www.copyright.gov/fair-use/mo...