Hawaii's intrepid “;samurai sub”; hunters will look this weekend for two Japanese World War II submarines that have eluded previous searches in a graveyard of military debris south of Oahu.

The Hawaii Undersea Research Laboratory's two submersibles, piloted by Terry Kerby and Max Cremer, have found three of five Japanese submarines with revolutionary technology captured by the U.S. Navy at the end of World War II and sailed to Pearl Harbor for inspection.

The submarines were designed to carry and launch folding-wing float plane bombers by catapult minutes after surfacing so they could attack the mainland United States and Panama. No missions were carried out.

“;Fortunately for us during the war, they were developed quite late, in 1944 and 1945, and in very small numbers,”; said Dr. Hans Van Tilburg, maritime heritage coordinator for the National Oceanic and Atmospheric Administration's Office of National Marine Sanctuaries in the Pacific region.

The most recent discovery of “;top secret”; Japanese submarines by HURL submersibles was announced yesterday by Kerby, the undersea lab's operations director and chief pilot, Van Tilburg and J. Mark Fowler, executive producer of a National Geographic Channel documentary, “;Hunt for the Samurai Subs,”; premiering Tuesday.

The submersibles found an I-14 submarine in February that carried two aircraft while submerged, and an I-201, one of the fastest WWII attack subs.

“;It was really propitious to find two of these subs fairly close together,”; Kerby said. “;It was a real risk we took going out on this site. It is very far from the site of recorded wrecks.”;

The deep-diving scientists found in 2005 the remains of an I-401 submarine that carried three aircraft.

The team will conduct test and training dives with the Pisces IV and Pisces V tomorrow and Sunday. They will do a maximum-depth dive, about 6,600 feet, Monday for certification.

They are also preparing for a monthlong expedition to the Papahanaumokuakea Marine National Monument in the Northwestern Hawaiian Islands for coral reef and fisheries research. The Hawaii Undersea Research Laboratory is operated by the University of Hawaii at Manoa and NOAA.

Kerby said they will look at a site Sunday where “;sketchy information”; indicates they might find one of the missing Japanese submarines. “;It's pretty far offshore. ... We may wander around looking at a lot of mud.”;

The National Geographic Channel partially funded and documented the search mission by submersibles for the Japanese submarines.

Fowler said the I-14 submarine was part of an I-400 class of Japanese submarines designed to go 37,500 miles, 1 1/2 times around the globe, without refueling to launch aircraft and drop bombs.

Primary targets were Panama, New York and Washington, D.C., he said.

The largest I-400 class submarines were 400 feet long—longer than a football field—and the I-14 was 375 feet long, he said.

Once the U.S. Navy studied the technology in the subs, “;they became a liability because Russian scientists also were demanding access to them,”; Fowler said.

Navy veterans said they were instructed to take them offshore, torpedo and sink them to keep them from the Russians, he said.

Kerby, in an interview, said the sea floor south of Oahu “;is like a giant underwater museum”; with debris from the Pearl Harbor attack and military wreckage.

He said his team began in 1992 using test and training dives before each dive season to look for maritime artifacts, starting with a Japanese midget sub sunk on Dec. 7, 1941. They found it in 2002.

HURL Director John Wiltshire said the submersibles operate together for filmmaking, with one providing lighting, and they now have high-definition cameras. “;They can make beautiful underwater images.”;

The Japanese were the first to produce aircraft-carrying submarines for attack purposes, he said. They could pop above the surface, assemble and launch aircraft within seven to 10 minutes, then submerge, Van Tilburg said. “;They were a true stealth weapon.”;

The U.S. Navy had no submarines as large as the Japanese submarines until ballistic missile submarines were designed, he said.