Hawaii's deep-diving submersible explorers have discovered two more of Japan's largest and fastest World War II submarines on the ocean floor off Oahu.

A Hawaii Undersea Research Laboratory team led by chief pilot and operations director Terry Kerby found the historic artifacts: An I-14 submarine which was used to carry two aircraft, and a 1-201, one of the fastest WWII attack subs.

Kerby and Max Cremer, piloting HURL submersibles Pisces IV and Pisces V, found the 60-year-old Japanese submarines in February while conducting test and trial dives. The team includes Colin Wolleman, Steve Price and Doug Boedern.

The ocean bottom south of Oahu “;is like a giant underwater museum,”; Kerby said in an interview, explaining his team uses test and trial dives to look for maritime artifacts. “;We've been pretty successful.”;

Their latest discovery was announced today by the National Geographic Channel and HURL, operated by the National Oceanic and Atmospheric Administration and the University of Hawaii at Manoa.

The Geographic Channel partly funded and documented the mission for a special, “;Hunt for the Samurai Subs,”; premiering Nov. 17 during the network's second annual Expedition Week.

The I-14 submarine is part of an 1-400 class of submarines developed by the Japanese with revolutionary technology to attack the United States mainland and Panama Canal. They were the largest submarines ever built—400 feet long—until nuclear-powered submarines emerged  in the 1950s and 1960s.

The U.S. Navy captured the submarines at the end of WWII and sailed five of them to Pearl Harbor for inspection. They included 1-400, 1-401 and I-14 aircraft-carrying submarines and two fast attack subs, 1-201 and 1-203.

“;The Hunt for the Samurai Subs”; tells how the Navy torpedoed and sunk the submarines off Oahu's coast, reportedly so the Russians couldn't see them at the start of the Cold War.

It includes film footage shot by Charles Alger, retired U.S. Navy chief in charge of the I-14, who described the sinking and said “;I never ever thought it would ever be seen by a human being again.”;

Kerby said he began using test dives before each dive season in 1992 to start looking for a Japanese midget sub sunk on Dec. 7, 1941. The submersibles found it in 2002.

In 2005, the HURL scientists found the wreckage of a huge 1-401 submarine that carried three aircraft. It was built to bomb the Panama Canal, according to reports.

John Wiltshire, acting director of HURL, said, “;These subs were bigger than nuclear subs, the largest diesel subs ever built. They could launch aircraft, stay submerged and run 37,500 miles—1 1/2 times around the globe—without refueling.”; He said the discovery is “;tremendously exciting. I think the National Geographic special will be outstanding. It is shot in high definition.”;