Two days before NFL player Marquis Cooper took a doomed fishing trip with three friends in Florida Gulf Coast waters, a friend urged him to buy a life-saving device used to locate boats in distress.

Cooper hadn't heard of the gadget, an emergency position indicating radio beacon (EPIRB). And he didn't purchase one before his excursion on Saturday, according to the St. Petersburg Times.

Cooper friend William Bleakley and fellow NFL player Corey Smith remain lost and presumed dead after their boat flipped over in rough seas Saturday.

A fourth man with them, Nick Schuyler, survived by clinging to the overturned vessel for 46 hours.

The Coast Guard never received a distress signal from Cooper's 21-foot fishing boat.

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His friend Clay Eavenson told him during a different fishing outing two days before the accident that he should get an EPIRB, which transmits radio signals and GPS coordinates that rescue crews can use to find boats in trouble, the Times reported.

The devices cost between $400 and $1,400 and can self-activate when boats tip over. Cooper agreed that he should have one — but didn't follow through before setting off Saturday. Eavenson had been invited to go with the four, but declined, according to the paper.

"The thing I want to come out of this is people need to become aware," Eavenson said. "He was not aware of what one was, and he would have had one had he known.

"He told me he was going to go buy one. There are literally hundreds and hundreds of people that do what Marquis did without knowing what is available."

The lone survivor said two of those lost gave up after hours in the frigid water and the third tried to swim to safety.

Former University of South Florida football player Schuyler told investigators that all four of the friends on the fishing excursion were initially wearing life vests and clinging to the boat belonging to Oakland Raiders linebacker Cooper.

But two to four hours after the boat capsized, one of the NFL players removed his life jacket and let himself be swept out to sea, the Times reported. A few hours later, the other one followed suit.

"We were told that Nick said the two NFL players took their life jackets off and drifted out to sea," said Bob Bleakley, whose son Will Bleakley, 25, is also still missing.

After Cooper, 26, and Corey Smith, 29, were carried away, Bleakley and Schuyler hung on until morning — but then Bleakley decided to swim to get help when he thought he saw a distant light, the paper said.

He, too, took his life vest off, 24-year-old Schuyler told the families.

"I think he was delusional to think he could swim someplace," the Times quoted Bob Bleakley as saying.

Cooper's cousin Ray Sanchez said the Coast Guard recounted a similar story to him, but doesn't know whether it's true. Schuyler suffered from hypothermia and weakness, which could have affected his memory and thinking.

"We're not 100 percent sure where his head was at," Sanchez told the paper. "He'd been through a lot."

His doctor said he was in good condition on Wednesday and had never been delusional during his ordeal.

"I don’t think he was thinking as well as you and I today," Dr. Mark Rumbak, the attending physician for the rescued boater, told reporters outside Tampa General Hospital. "But I don’t think he was delusional at all."

Meanwhile, family and friends refused to give up the search for the three men missing four days in the Gulf of Mexico, enlisting private boats and planes to comb Florida waters after the Coast Guard stopped its official search late Tuesday.

About a dozen charter boats motored out Wednesday, some with friends of the families aboard, to try to locate some sign of the men, according to dock workers at John's Pass near St. Petersburg. Three private planes also flew over the endless stretch of water, according to Cooper's father.

"Everyone around here, they've either known someone or heard of someone who's been lost out at sea," said David Scott, who works at a marina at John's Pass. "It's just one of those situations. Everyone really comes together in times like these."

Schuyler was rescued Monday after a Coast Guard cutter crew found him clinging to the hull 35 miles off Clearwater. His doctor said it's a "miracle" Schuyler survived in the 63-degree Gulf water for nearly two days.

Rumbak attributed the fitness instructor's survival for 46 hours in 60-degree waters to the good shape he's in physically, his mental stamina, his experience playing college football — and luck.

"This guy is very tough mentally. ... If he didn't have that type of background, I don't think he would have made it," Rumbak said. "Still, I do think it's a miracle."

On Wednesday night, Florida Fish and Wildlife crews retrieved the overturned boat and brought it back to shore.

The Coast Guard ended its three-day search for the men Tuesday at sunset, dashing hopes they might be found.

Rescuers combed more than 24,000 miles of ocean before calling it off.

Coast Guard Capt. Timothy Close said if there were any other survivors, they would have been found.

"I think the families understood that we put in a tremendous effort," Close said. "Any search and rescue case we have to stop is disappointing."

Coast Guard teams spotted no signs of the men except for a cooler and a life jacket 16 miles southeast of the boat. Still, family members of Cooper — the son of Phoenix sportscaster Bruce Cooper — maintained hope at a Tuesday night prayer vigil in Mesa, Ariz., that he might turn up.

Bleakley's father said he thought Coast Guard rescuers did everything they could, adding he had lower expectations after only one survivor was found Monday.

"I think they were not to be found," Robert Bleakley said.

Scott Miller, a friend of the college teammates, said Schuyler told him that a chopper shone a light directly above them the first night. Schuyler also told him he even saw lights beaming from ashore.

It was Bleakley who swam underneath to retrieve three life jackets he could find, along with a cushion, a groggy Schuyler told Miller from a Tampa hospital. Bleakley used the cushion and the other men wore the jackets, Miller said.

But the waves were powerful, and after Cooper and Smith were separated from the boat, the college teammates tried to hang on.

"He said basically that Will helped him keep going," Schuyler told Miller, who said he had known Bleakley since the sixth grade. "The waves were just so much. They never got a break."

Schuyler's doctor said he hasn't seen signs of post traumatic stress yet and doesn't believe that Schuyler has fully grasped the gravity of the situation — which is normal immediately after a crisis. But Schuyler knows his friends are lost, he added.

"I think he is aware of what happened to his friends," Rumbak said. "He said he was fine at this point in time. I don't think it's fully hit him yet." He said he was reunited with his girlfriend and "seemed quite happy."

The four men left Clearwater Pass early Saturday in calm weather, but heavy winds picked up through the day and the seas strengthened, with waves of 7 feet and higher, peaking at 15 feet on Sunday.

Schuyler told the Coast Guard the boat was anchored when it capsized.

The Coast Guard hadn't had more detailed conversations with Schuyler because of his physical condition, Close said. Schuyler told hospital officials he didn't want to speak to the media.

Cooper was selected in the third round of the 2004 NFL draft by the Tampa Bay Buccaneers out of Washington. He played 26 games for the Bucs in his first two pro seasons, then led a nomadic NFL existence.

Cooper and Smith became friends when they were teammates at Tampa Bay. Smith signed with the Bucs as an undrafted free agent in 2002, and spent last season with Detroit before becoming a free agent. The former North Carolina State standout recorded 42 tackles (28 solo), three sacks and 10 special teams tackles in 2008, his best NFL season.

Bleakley, a former tight end from Crystal River, Fla., was on the USF football team in 2004 and 2005. He had one reception for 13 yards in his career, which also included some time on special teams.

Stuart Schuyler said his son is an instructor at L.A. Fitness and had helped train Smith and Cooper.

Click here for more on this story from MyFOXTampaBay.com.

Click here for more on this story from the St. Petersburg Times.

FOXNews.com's Catherine Donaldson-Evans and The Associated Press contributed to this report.