A team of researchers discovered a World War II-era Japanese submarine the length of a football field in August off the coast of Oahu, Hawaii, officials said.
Terry Kerby, of the Hawaii Undersea Research Laboratory, the organization that found the submarine, said they had to wait to unveil their discovery to the public until they had complete confirmation of the submarine's identity.
After a back-and-forth between the U.S. State Department and the Japanese government, it was determined the submarine was the I-400, KITV-TV, Honolulu, Hawaii, reported Monday.
"We couldn't really see the tell-tale sign number I-400 painted on the side like we saw with the other subs, but we saw features of it that match it up with the I-400," Kerby said.
Kerby said the team found the submarine by following a cable they found about three miles from Barbers Point in 2,300 feet of water.
"There was a communications cable and it was coming out of the bottom into space and so we knew it was pretty big and so we followed this cable and out of this darkness came this massive bow, and it was a thrill," he said.
The submarine was one of five Japanese submarines docked at one time in Pearl Harbor. The U.S. Navy sank the vessel, which was big enough to hold three airplanes with foldable wings nose-to-tail, the newspaper said.