Updated

A daughter of hockey great Bob Gainey was still missing Monday after she was washed overboard in the Atlantic during a storm while working on a sailing ship bound for the Caribbean.

A Canadian C-130 Hercules has joined the search for Laura Gainey, who was thrown from the 180-foot boat Friday night and was not wearing a lifejacket. The search aircraft relieved an American plane that had been scouring the ocean for the 25-year-old daughter of the Montreal Canadiens' general manager.

Matthew Brooks, a civilian search and rescue specialist with the U.S. Coast Guard, said there was still no sign of her.

She was aboard the Picton Castle, a training vessel, when a wave tossed her into the sea about 475 miles southeast of Cape Cod, Mass. The crew dropped radar deflectors and lighted buoys in the water when they realized she was missing.

Click here to go to FOXNews.com's Americas Center.

Brooks said U.S. air rescuers used infrared night-vision goggles to search the dark waters late Sunday. American and Canadian search aircraft later dropped data buoys in the area.

"They talk to us via satellite, and they send us positions on the hour," Brooks said. "This is the best way to tell us how the water is moving."

Gainey is a good swimmer and was wearing warm protective clothing. She has been in the water about 60 hours, and the U.S. Coast Guard says life-threatening hypothermia ordinarily sets in after 36 hours.

With the weather improving Monday, two merchant vessels and the sailing ship remained in the area and a Hercules from North Carolina was expected to join the search this afternoon.

Gainey climbed aboard the square-rigged, three-masted ship last spring in Cape Town, South Africa. The ship's Web site shows a photo of her in a swim suit and laughing.

Dan Moreland, the ship's senior captain, said from Lunenburg she had become a "well-loved," enthusiastic volunteer on the vessel. He described the situation as "completely devastating for everybody" on the boat. The ship is mainly used to provide adventurous holidays for anyone over 18.

The Canadiens said assistant general manager Pierre Gauthier will handle Bob Gainey's responsibilities for now. Gainey also holds the title of executive vice president.

A member of the hockey Hall of Fame, Gainey won five Stanley Cups with Montreal during a 16-year career from 1973-89. He also won a championship as general manager of the Dallas Stars in 1999. His wife, Cathy, died of brain cancer in 1995 at 39.