The main mission of the Hawai'i Undersea Research Laboratory isn't to chronicle the many military ships and planes it locates beneath the waves.

Rather, it's to study deep-water marine processes in the Pacific.

But thanks to training and trial dives in two submersibles, the Pisces IV and Pisces V, the lab has made some amazing historical finds, and done some pretty good detective work on top of it.

The latest in a long line of notable discoveries may be a Douglas SBD Dauntless that was shot down on Dec. 7, 1941.

Steve Price, a submersible technician and co-pilot, recently had time to look more at imagery of the tail section of an SBD that was located in 2005 in about 760 feet of water south of 'Ewa Beach.

There was a small U.S. star with a "meatball" in the center.

"That was only used in late '40 and into '41, and after Pearl Harbor, they made the star bigger, and eventually, took the meatball out of it," Price said.

Price is "pretty sure" the Navy dive bomber is that of Ensign Walter M. Willis and his gunner, Fred J. Ducolon, who were sent aloft with other SBDs from the aircraft carrier USS Enterprise to scout the waters ahead, but instead ran into the Japanese aerial invasion.

Willis and Ducolon are believed to have been shot down. Neither crew member nor the plane was ever found.

The tail section was located by the Hawai'i Undersea Research Laboratory outside some of the known military dumping grounds that are a veritable undersea military museum, Price said.

"So it's not something that was likely jettisoned," he said.

The training dives in March 2005 were incredibly productive in terms of history.

On the same day the SBD tail section was identified, the research lab, which was established by the National Oceanic and Atmospheric Administration and the University of Hawai'i, discovered the S-19, a World War I-vintage submarine that was scuttled off Pearl Harbor in about 1938.

The sub sits upright in about 1,300 feet of water.

An even bigger find was made two days later with the discovery of the huge Japanese World War II submarine I-401, which was sunk during target practice in 1946.

The 400-foot sub was designed to carry and launch aircraft. According to the research lab, the war ended before the big sub could fulfill its mission of launching its three planes to attack and destroy the Panama Canal.

The submarine, brought back to Hawai'i and sunk in torpedo practice, is in two pieces, but sits upright five stories tall in 2,854 feet of water off Barbers Point.

Price does a lot of data entry for the finds. With the discovery of the S-19 and the I-401, and then a long trip to New Zealand and back, the SBD Dauntless went on Price's back burner until he got back to it recently.

Someday, he'd like to document the rest of the history of the dive bomber he believes was a Dec. 7, 1941, veteran.

"I'd love it if we could ever get an opportunity to go back, because you can only imagine that the rest of that plane is going to be within a couple hundred meters," Price said.

IN BRIEF

HOSPITAL SHIP DUE BACK IN ISLES TODAY

The hospital ship USNS Mercy is scheduled to arrive in Pearl Harbor at 10 a.m. today following the conclusion of its Pacific Partnership 2008 mission in the Western Pacific.

The crew of the Mercy then will make the final leg of the journey to the ship's homeport of San Diego.

The joint multinational and nongovernmental crew that made up the Mercy departed San Diego on May 1. For four months the crew provided humanitarian assistance in the form of medical, dental and engineering projects to the Republic of the Philippines, Vietnam, Timor-Leste, Papua New Guinea and the Federated States of Micronesia

U.S. Navy Seabees in Chuuk State, Federated States of Micronesia, completed the final mission on Sept. 12.

More than 90,000 patients were treated, more than 14,000 dental patients were seen and more than 1,300 surgeries were conducted aboard the Mercy.

"Pacific Partnership reminds everyone, everywhere around the globe, that we are dependent on other people," said Wesley Simina, governor of Chuuk State, Federated States of Micronesia. "We will forever be grateful to be a part of this monumental occasion."

Twenty-six engineering projects were completed during Pacific Partnership, the Navy said. These projects ranged from the construction of a wastewater treatment facility in the Philippines to the construction of a community center in Papua New Guinea.

The Mercy team also included volunteers from organizations such as Operation Smile, Project Hope, University of California Pre-dental Society, East Meets West and International Relief Teams.

Pacific Partnership is a humanitarian civic assistance mission considered to be at the core of the Navy's maritime strategy.

POWS/MIAS TO BE HONORED FRIDAY

The Joint POW/MIA Accounting Command will commemorate National POW/MIA Recognition Day at the National Memorial Cemetery of the Pacific at Punchbowl at 10 a.m. Friday.

Each year, a presidential proclamation designates the third Friday in September as National POW/MIA Recognition Day. The ceremony is open to the public.

Reach William Cole at wcole@honoluluadvertiser.com.