Lt. Jessica Hill, 30, of St. Augustine, Fla., and Petty Officer 2nd Class Steven Duque, 26, of Miami, were diving beneath the Coast Guard Cutter Healy to inspect the ship's rudder.

The cutter, which is based at Pier 36 in Seattle, was in the Arctic Ocean about 500 miles north of Barrow, Alaska conducting scientific research when the divers died.

Coast Guard officials declined to provide details of the incident and said the deaths were under investigation.

They described the shallow dive as a cold water familiarization exercise in which the divers were near the bow of the ship.

Divers will routinely inspect the hull and rudder of ships that are operating in Arctic ice. Before such dives, the ships stop and propellers are disengaged while the divers are under water.

"I felt a deep sense of loss when I received the initial report on this situation," said Vice Adm. Charles D. Wurster, Commander, Coast Guard Pacific Area, in a news release issued by the Coast Guard. "I offer my prayers to the families and friends of Lieutenant Hill and Petty Officer Duque in their time of grieving."

The cutter was expected to dock in Alaska to pick up Coast Guard investigators, and it's not known when the ship will return to Seattle, a Coast Guard spokesman said.

The Healy is a 420-foot cutter outfitted with scientific research equipment and is one of three ice breakers operated by the Coast Guard.