PLANTATION, Fla. -- The former NFL fullback entered the room with a wobble in his walk, and needed assistance climbing a podium so he could face a media throng and discuss his death-defying 16-hour swim to shore.

Rob Konrad sipped from a bottle of water, his efforts to rehydrate ongoing four days after the episode. His wife sat at his side rubbing his leg in support, and tears welled in their eyes as he spoke Monday.

Rob Konrad described how he survived 16 hours in the water last week after falling from his boat. AP Photo/Lynne Sladky

"Happy to be here," he began with a wry smile.

"I shouldn't be here," he said later, his voice cracking.

The 38-year-old Konrad's escape was a testament to willpower and world-class athleticism. The first reports of his adventure last week received worldwide attention.

"It's an incredible story," endurance swimmer Diana Nyad said. "Taking his life in his hands and deciding he was going to save himself, I admire him."

Konrad, who played for the Miami Dolphins from 1999 to 2004, had been around boats since his childhood on Boston's North Shore. So he knew what it meant when he fell off his 31-foot Grady-White while fishing alone nine miles from land.

"A boater's nightmare," he said.

He swam to Palm Beach, covering a distance of 27 miles before ringing the doorbell of an oceanfront home for help at 4:30 a.m. Thursday.

The U.S. Coast Guard last week provided a brief summary of the events. Konrad, still weak after several days in the hospital for treatment of hypothermia and dehydration, held a news conference to fill in the details.

They were hard to believe, he and his wife agreed.

"It was a miracle he made it home," Tammy Konrad said.

Her husband said he was taking his boat for servicing last Wednesday and decided to do a little fishing along the way. He had caught a large fish and was tending to the Rob when a large wave hit, flipping Konrad into the ocean.

His boat was on autopilot and headed east. There were no other boats in sight. Konrad wasn't wearing a life preserver. It was 12:30 p.m.

"I realized I was in some real trouble," he said.

Konrad quickly decided to swim toward shore, although he figured the trip would take more than 10 hours, and feared succumbing to hypothermia or cramps after two or three hours. The ocean temperature was in the low 70s -- far from frigid, but a lot colder than his body temperature.

So Konrad decided he'd better keep moving. He took off his shirt and began alternating between a breaststroke and backstroke.

He said he's not much of a swimmer, but Nyad figures his football experience made a big difference.

"We're not really talking about a swimming story. We're talking about a survival story," Nyad said. "I'm sure his background as an athlete -- toughness, having resolve, knowing things are going to be painful -- were the saving grace for him."

Konrad said he got bit "by a whole bunch of stuff." A shark circled before moving along.

"There was a lot of stuff glowing at night, probably some jellyfish," he said.

He could also see lights along the coast and pick out landmarks. As he tired, he gained emotional strength.

"Five or six hours in I realized, 'Maybe I can do this,'" he said.

Twice he was nearly rescued. A recreational fishing boat approached to within 50 yards, but Konrad couldn't flag it down. Then a Coast Guard helicopter searching for him flew overhead.

"They had their lights on me and kept going," Konrad said. "They didn't see me. That was a difficult time."

But the ex-Dolphin kept swimming, thinking of his daughters, ages 8 and 10.

"He had two angels on his back," his wife said.

"I was probably pretty delirious at the time, but I could see the lights getting closer and closer," he said.

Then the sound of the ocean changed. He could hear waves hitting the shore, and finally he reached land.

"The problem was I couldn't walk. My body was shaking uncontrollably. I crawled up on the beach and warmed myself up enough to be able to walk."

Paramedics were summoned, and soon he was en route to the hospital. His boat was found near Grand Bahama Island on Deadman's Reef, the irony of the name not lost on Konrad. He had gone the other way.