PORT FOURCHON, La. (NewsNation Now) — Coast Guard boats and aircraft have covered an area larger than the state of Rhode Island to search for 12 people still missing Wednesday off the Louisiana coast after their offshore oilfield vessel capsized in hurricane-force winds.

One worker’s body was recovered Wednesday and six people were rescued Tuesday after the Seacor Power overturned Tuesday afternoon in the Gulf of Mexico, the Coast Guard said.

The search, interrupted by darkness and bad weather, has totaled nearly 40 hours and more than 1,440 square miles of Gulf waters by Wednesday afternoon, according to a news release. The hunt for the missing continued into the evening, said Petty Officer Carlos Galarza.

“As of now, we have rescued six survivors who were safely transferred ashore. Unfortunately, we recovered one individual on the surface of the water deceased,” Captain Will Watson, Coast Guard Sector New Orleans, said during a press conference Wednesday. “The search effort continues for the remaining 12.”

Captain Watson said the details that led up to the turnover are under investigation, but he said winds were up to 90 miles per hour at the time the boat capsized and seas were 7 to 9 feet. Watson says the vessel was headed to Main Pass.

The bulky vessel, also called a jackup rig because it has three long legs it can lower to the sea floor to lift the boat out of the water as an offshore platform, flipped over Tuesday afternoon south of Port Fourchon, a major base for the U.S. oil and gas industry.

Asked about the prospects of the missing crew, Watson said: “We are hopeful. We can’t do this work if you’re not optimistic, if you’re not hopeful.”

Divers were heading to the local area Wednesday afternoon, Coast Guard spokesman Petty Officer John Micheli said.

Lafourche Parish-President Archie Chaisson told NewsNation affiliate WGNO that six people were rescued, however, three people had to be left behind, clinging to the partially sunken vessel because weather and water conditions were too rough to retrieve them.

“The hope is that we can bring the other 12 home alive,” Chaisson said. Time is of the essence in the rescue efforts, as “we have the potential for some rough weather around lunchtime,” he added.

Relatives of the missing crew members rushed to the port from their homes nearby, seeking any information they could get, Chaisson said.

Marion Cuyler, the fiancée of crane operator Chaz Morales, was waiting with family of other missing workers at a Port Fourchon fire station near a landing site where helicopters were coming and going. She said she talked to her fiancé before he left Tuesday.

“He said that they were jacking down and they were about to head out, and I’m like, ‘The weather’s too bad. You need to come home.’ And he’s like, ‘I wish I could.’”

Credit: Bruce J Simon via Storyful

The company involved, Houston-based Seacor Marine, set up a private hotline to share information with families of those onboard, Chaisson said. An employee who answered the phone Wednesday morning said he had no immediate information he could share.

The National Weather Service in New Orleans had advised of bad weather offshore, including a special marine warning issued before 4 p.m. Tuesday that predicted steep waves and winds greater than 50 knots (58 mph).

The Coast Guard received an emergency distress signal at 4:30 p.m. and issued an urgent marine broadcast that prompted multiple private vessels in the area to respond, saving four crew members, the agency said. Coast Guard crews rescued another two people.

The Coast Guard then issued an urgent marine broadcast that prompted multiple private vessels in the area to respond, saving four of the crewmembers, the agency said. Coast Guard crews in boats rescued another two people. A search plane also joined the effort, miles south of Port Fourchon.

Although the Coast Guard said the lift boat capsized during a microburst, a National Weather Service meteorologist said the system was more like an offshore derecho.

“This was not a microburst — just a broad straight-line wind event that swept over a huge area,” Phil Grigsby said.

He said the weather service’s nearest official gauge, at Grand Isle, showed about 30 minutes of 75 mph (120 km/h) winds, followed by hours of winds over 50 mph (80 km/h).

The initial storm system was followed by a low-pressure system called a wake low, which amplified the winds and made them last longer, Grigsby said. “It was the strongest wake low I’ve seen in almost 18 years here,” he said.

Capt. Ronald Dufrene said his offshore trawler, Mister Jug, was among the shrimp boats that struggled to survive.

“People who have been fishing 30, 40 years — the first time they put their life jackets on was yesterday. … I know three boats for sure said that,” Dufrene said.

He said the captain who was on board his boat told him seas rose 15 to 20 feet (5 to 6 meters) and the wind gauge was lost at 80 mph (129 km/h), but a crewman told him later that he saw the gauge at 95 mph, “then the wind laid the pole over.”

The 95-mph (153 km/h) report can’t be taken as official, Grigsby said. “We don’t know how well-calibrated their instrument is. But it’s not outside the realm of probability,” he said.

The Seacor Power, a bulky vessel 129-feet long at its beam, is designed to become an offshore platform by dropping three towering legs down to the sea floor.

Port Fourchon, Louisiana’s southernmost seaport, is a major base for the U.S. oil and gas industry, supporting most of Louisiana’s offshore platforms and drilling rigs.

The storm also overturned other vessels and damaged property from Louisiana’s shore up to New Orleans.

“Please join @FirstLadyOfLA and me in praying for those who remain missing after yesterday’s capsizing off the coast of Grand Isle and for those who are working to rescue them,” Louisiana Gov. John Bel Edwards said Wednesday on Twitter.