"They're actually in amazing shape considering these were torpedoed. They're on the bottom and they've sat there for over sixty years," said John Wiltshire of the University of Hawaii's Hawaii Undersea Research Laboratory (HURL).
Until February of this year no one knew exactly where the submarines were. But researchers had an idea. They zeroed in using coordinates from the wreckage of another Japanese sub.
"These submarines are about five miles off Barbers Point in about 3,000 feet of water," Wiltshire said.
Aboard the submersibles Pisces IV and V, NOAA and National Geographic found them and filmed them for a documentary.
Scientists describe the sight as astounding.
"These were 400-foot long submarines," Wiltshire said. "They could stay submerged and sail one a half times around the world. That's 37,000 miles."
One of the subs is the I-14, an underwater aircraft carrier.
"These submarines could actually come to the surface and launch three large aircraft and they could purportedly do that within fifteen minutes," he said.
Then there's the I-201, one of the fastest attack subs of its day.
"These things could go at nineteen knots underwater at a time when U.S. comparable submarines could go at six knots," he said.
Records and eyewitness accounts say Japan planned to use the submarines to attack the Panama Canal, New York and Washington, DC.
After Japan surrendered the U.S. Navy sank the submarines, reportedly to keep the technology from the Soviet Union.