NEW BEDFORD — A Coast Guard jet screeched over Nantucket Sound Thursday broadcasting a severe weather warning to vessels below: an advancing front would plunge overnight temperatures into the single digits, create lashing winds of 45 knots over the waters of Georges Bank and produce seas of 22 feet.

Beware.

Antonio Barroqueiro, the captain of the Lady of Grace, and his three-member crew heeded the warnings. By Friday afternoon they had pointed the bow of the 75-foot dragger back toward New Bedford, their eight-day trip for groundfish now cut in half.

As the afternoon wore on and the winds picked up, the fine spray from the 34-degree water presented the most weighted danger to offshore fishermen in winter: ice.

Silently it encrusted the boat’s railings and cables. It encased its superstructure and the roof of its pilot house. With 100 years of fishing experience among them, Barroqueiro and his crew knew the risk the white rind presented.

Unless they continued banging and smashing it off — a relentless and exhausting chore, particularly on an icy deck — the weight of the ice could make the boat top-heavy and cause it to roll over.

But sometime Friday evening, Coast Guard investigators say, the worst of the scare appeared over.

A crew member called the boat’s owner in New Bedford about 6 p.m. The crew had labored for hours breaking up the ice, the crew member reported. Despite current conditions of 30-knot winds and 10-foot seas, the boat should make it back to port on time — around 5 a.m. Saturday.

It never did.

Late Saturday, Coast Guard search crews — drawn by an oil slick about 11 nautical miles north of Nantucket and using sonar and underwater cameras — discovered the boat resting on the bottom of Nantucket Sound in 36 feet of water.

Divers on Sunday afternoon confirmed the discovery. Through turbid water offering only 2-foot visibility, they saw the boat resting on its port side — its only lifeboat still lashed to the deck.

Yesterday afternoon, state police divers recovered one body from the sunken vessel. Divers found the body at about 2:30 p.m. in the wheelhouse of the Lady of Grace after diving for nearly nine hours, the state police said in a statement last night. The body, which has not been identified, was taken to the State Medical Examiner’s Office in Boston.

Coast Guard officials contacted the families of the missing fishermen and told them that one body was located, state police said.

The boat sank only one mile from where the crew member reported the boat’s last position during his phone call with the owner, prompting speculation that whatever happened, may have happened quickly thereafter.

“We don’t know how much time the crew had,” said Coast Guard Lt. Cmdr. Patrick Cook, who headed the search effort.

Yesterday morning the Coast Guard suspended its search for Barroqueiro, Rogerio Vendura, Mario Farinha and João Silva — the latest to die here in one of the most dangerous, yet familiar, of occupations.

“It is beyond probable, beyond possible, that they could still be viable and have survived at this point,” Cook told reporters.

Although ice build-up remains the leading theory for the sinking, investigators were also looking into the possibility that the Lady of Grace may have lost power, which would have made it difficult to maneuver, especially if weighed down by ice.

Earlier this month the Coast Guard had to tow the vessel to safety after it reported it lost power and was drifting near Nantucket.

And at 10 p.m. Friday, a telecommunication service called BoatTrax, which for a fee tracks boats via satellite, reported losing contact with the Lady of Grace.

Reports of that lost contact, along with the vessel not returning to port when expected, prompted the Coast Guard to launch its search, about 8 a.m. Saturday.

“All of those questions will be looked at in detail,” said Cook.

Investigators were also looking into the veracity of a report that a boy flying aboard a small plane Saturday from Hyannis to Nantucket spotted what appeared to be a body floating in the water.

The sinking was the deadliest fishing accident involving a New Bedford-based boat since five of six crew members of the scalloper Northern Edge died in a sinking on Dec. 20, 2004.

Despite decades of strict fishing restrictions, which have put many New England fishermen out of business, about 350 fishing vessels still tie up to the docks in New Bedford, said Mayor Scott W. Lang, making it the largest fishing fleet in the nation.

“New Bedford is defined by its fishing fleet,” Lang said hours after informing family of the lost men that the search had been suspended. “I don’t think there is anyone in this city who is not waking up and saying a prayer for these people.”

Lang said he hoped some good might come from the tragedy. For instance, it is time, he said, that the federal government reexamine its current fishing regulations, which as currently written are based on the number of days a boat can leave port rather than by the total tonnage of fish it can catch.

The regulations now force fishermen to venture out into dangerous conditions, he said, rather than wait to fish in calmer weather.

The disaster, the mayor said, might also lead to the design of less cumbersome, more flexible survival suits. Current survival suits, which can keep a fisherman alive for hours in freezing water, are bulky and take time to properly put on.

Coast Guard investigators said the Lady of Grace had enough survival suits on board but it was unclear if any members of the crew had time to don them.

Mayor Lang acknowledged, however, that even with these changes, the circumstances of the sinking could have happened so fast that it’s just “a disastrous calamity you can’t react to.”

That sense of sad acceptance seemed apparent yesterday at the bar of the United Fisherman’s Club, where the state flag and the Portuguese flags flew at half staff and the sinking was on the lips of a half-dozen mingling fishermen.

Mario Pereira, 50, is a captain himself who has fished out of New Bedford for 35 years. He knew Barroqueiro and the engineer of the Lady of Grace. Both were experienced men, he said, who from all reports did everything they could to try to get home.

That they died anyway, gave him some pause. But not much:

“When you are born to be a fisherman,” he said, “you are ready to face whatever problems you face.”

Material from the Associated Press was used in this report.

tmooney@projo.com