Former NFL fullback Rod Konrad made a media appearance on Monday to recount his 27-mile swim to shore over 16 hours after he fell off his 31-foot Grady-White fishing boat.

“I shouldn’t be here,” he said, his voice cracking. The 38-year-old was sipping water, still trying to rehydrate four days after the event, according to a report in the Standard Examiner.

“I’m grateful and thankful to be here,” he said during a press conference in Plantation, Fla., where he recounted jellyfish stings, a circling shark and two near-rescues, according to the Sun-Sentinel.

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

Last Thursday morning, the former Miami Dolphins fullback was taking his 31-foot boat from Lighthouse Point to Riviera Beach for service. Along the way, he put the boat on autopilot and began to troll. A big fish hit a line. As he moved the rod, a huge wave hit the boat, knocking him overboard.

Konrad, who played for the Dolphins from 1999 to 2004, had been around boats since his childhood on Boston’s North Shore. Konrad figured he had two or three hours before hypothermia or cramps set in. He decided to start swimming west toward land in hopes of running into another boat.

“In the next 16 hours, I really had two opportunities for rescue,’’ he said. “At one point, as I swam into the night, there was a fishing boat, a recreational fishing boat, about 50 yards away. I tried to flag down the boat. It didn’t work out.”

“A little bit later on, I saw the Coast Guard [helicopter]. They were out, searching the water. At that point in time, came right over the top of me. They had lights on me, but kept going. That was a difficult time. I realized at that point I was on my own.”

Konrad said he prayed for help and thought of his family with his wife, Tammy, and two daughters, ages 8 and 10.

“After some time I just said, ‘Look, I’m not dying tonight, I’m going to make it to shore,’ ” he said. “It certainly tests your mind when you’re in the water that long.”

There were moments when he wasn’t sure he would make it. He thought it was about midnight and not 4:30 a.m. when he came ashore near a Palm Beach home. At that point he was too weak to walk. He had to curl up first and warm his body so it could move to the house and get help.

Konrad was hospitalized from Friday morning until Sunday and was treated for hypothermia and severe dehydration.

”Unfortunately, I ended up in a boater’s nightmare and was lucky enough to survive,’’ he said.

“It was a miracle that he made it home,” Tammy Konrad told reporters. “It was beyond terrifying.”

“It’s an incredible story,” endurance swimmer Diana Nyad told the Standard Examiner. “Taking his life in his hands and deciding he was going to save himself, I admire him.”