A "Semester at Sea" research ship with 990 people on board was temporarily disabled in the Pacific Ocean on Wednesday, and Coast Guard vessels and aircraft from Alaska and Hawaii were dispatched to help.

The 591-foot Explorer lost power in three of its four engines when a 50-foot wave broke bridge windows, damaged controls and injured two crew members, the Coast Guard said.

The ship for a time operated on just one of its four engines and could do little more than keep the bow headed into heavy seas using emergency steering.

By Wednesday evening, a second engine had been started and the ship was making headway at a speed of about 10 knots in 35-foot waves and wind gusts of more than 50 mph, said Coast Guard spokesman Lt. Cmdr. Glynn Smith in Alameda, Calif.

The Coast Guard received word of the Explorer's situation at about 2:30 p.m. Alaska time.

The ship was reported about 650 miles south of Adak, Alaska. Adak is in the Aleutian Islands (search) about 1,300 miles southwest of Anchorage.

The Explorer is a 25,000-ton, Bahamian-flagged vessel that was en route to Korea and Japan from Vancouver, British Columbia. Stellar Maritime S.A. (search) is the owner. It was built in 2001.

Of the 990 people aboard, 681 are students and 113 are faculty and staff. The other 196 are ship's crew.

Paul Watson, director of enrollment management for the Institute for Shipboard Education (search), said Semester at Sea (search) is a global comparative study-abroad program for undergraduate students. About 650 take part at one time.

They can choose from 70 courses taught by faculty with international experience, including world history, international business, cultural anthropology and world music, Watson said. The program is academically sponsored by the University of Pittsburgh (search).

"The idea is to develop a more global perspective, exploring people of other countries, other cultures, particularly in the non-Western world," Watson said.

The 100-day voyage began Jan. 18 in Vancouver.

Watson said no students, faculty or staff had been injured. A medical staff of two doctors and two nurses is on board.

The ship never lost internal electrical power and maintained good communications with the Coast Guard, Smith said.

Among the units responding was the Jarvis, a 378-foot Coast Guard Cutter that departed from Dutch Harbor in the Aleutians. Reaching the vessel could take two days, Smith said.

Three Coast Guard HC-130 long-range aircraft also were en route, including two from Kodiak, Alaska, and one from Barbers Point, Hawaii.

The Explorer was about 1,600 miles from Honolulu and 800 miles from Midway Island.

The Coast Guard also directed four merchant vessels to divert and assist the stricken vessel.

Jim Lawrence, a spokesman for V. Ships, the technical managers of the ship, said he did not have details of injuries.

"I do know that nothing is critical," he said.

Ship managers will look at weather information and determine the most comfortable route for the ship and its passengers, he said.

"It looks like it may well be to head to Midway Island," Lawrence said.