A U.S. Coast Guard official says his agency has suspended the search for 25-year-old Laura Gainey, who is lost in the Atlantic Ocean.

Petty Officer Larry Chambers told CTV Newsnet on Monday that the agency's computer models suggested Gainey could survive for up to 36 hours.

"It's now been about 70 hours," he said.

While the Coast Guard has ended its search, the Picton Castle will continue looking and is in contact with the U.S. Coast Guard, Chambers said from Portsmouth, Va.

Daniel Moreland, the ship's senior captain, told the Canadian Press earlier on Monday that the ship and crew continue to search for Gainey.

"They are tired and, like us, they are devastated,'' he said. "But they soldier on. They have a job to do. So do we.''

The Canadian Coast Guard has also been working with both their U.S. counterparts and the ship, Chambers said.

A rogue wave apparently knocked Gainey -- daughter of Bob Gainey, general manager of the Montreal Canadiens -- off the rear deck of the tall ship Picton Castle on Friday evening.

She went overboard about 760 kilometres off the coast of Cape Cod, Mass. The Picton Castle had been en route to Grenada.

Chambers said the C-130 Hercules aircraft is equipped with night vision goggles for the eight-person crew, infrared detectors to locate someone based on their body heat, specialized radar and zoom cameras.

While the aircraft spotted the floatation devices and radar deflectors thrown overboard by the Picton Castle, Chambers said their searchers saw no trace of Gainey herself.

Gainey family in seclusion

Bob Gainey has been holding a vigil in Montreal with family, specifically his three other children. He has temporarily stepped down from his role with the NHL franchise.

The home port of the Picton Castle is Lunenburg, N.S..

On the waterfront there, two black pillars stand to remember those lost at sea.

"I didn't have to know her, but she was a sailor," local letter carrier Nancy Rogers told The Canadian Press. "They all have the same heart. They go to sea, knowing that's what they want to be doing.''

Gainey was a trainee with the 55-metre ship, and had previously taken part in a three-month voyage from Cape Town, South Africa to Lunenburg. The Caribbean expedition was her second with the ship.

"She became a very loved crew member, she was a lot of fun, friendly and cheerful and dedicated," said Moreland.

While she was not a professional sailor, Gainey was a strongly experienced amateur. She helped train some volunteer trainees.

Gainey wasn't wearing a lifejacket when she went overboard,  the victim of an especially large wave. Nor was she secured to the vessel by a safety line.

It isn't clear what she was doing on the deck at that time. Wind speeds had reached up to 75 kilometres per hour and swells were in the seven-metre range.

Former crew member Bart Sutherland sailed with Gainey earlier this year and remembered her fondly.

He stressed she had lots of experience on a tall ship as she had sailed on a similar vessel before joining the Picton Castle.

"She was definitely not a novice ... She knew her way around the ship. She had gone through many, many safety drills,'' he told CP.

"Safety is drilled into absolutely everyone onboard that ship. I know for a fact she was not careless. She would not have been doing something silly when the accident happened.''

However, he confirmed that crew members would not tether themselves to the ship.

There is no explicit rule requiring sail training vessels to have lifelines available, Transport Canada spokesman Maurice Landry told CP.

In any event, the ship is registered in the Cook Islands and isn't subject to Canadian safety rules, he said.

No complaints have been raised with Transport Canada about the vessel, he said.

Owned and operated by the Windward Isles Sailing Ship Company, the ship has berths for 40 trainees and 12 professional crew members. It has taught hundreds to sail the high seas over the last decade, completing four around-the-world voyages.

While a two-week trip costs $2,100, a six-month voyage costs $20,000. The six-month apprenticeship allows people to become qualified square-rigged seafarers.

With files from The Canadian Press