NEW ORLEANS — John Anders had been drifting in the Gulf of Mexico for an hour when he realized he was being circled by a shark.

The professional diver had lost his grip on a nearby oil rig while wrestling with a fish he had speared, and was adrift in open water, alone with no boat, miles from safety.

Foolishly, Anders had refused to let go of his catch, and it had drawn the shark's attention.

Now it was the fish or his life.

"I realized the only reason that shark would mess with me was for the grouper, so I fed it the thing," he said.

It was the first of two critical decisions the New Orleans diver would make to ensure his survival after four harrowing hours in cold, choppy Gulf waters, nowhere near land.

The tale of his rescue is one he will always carry with him.

Early on May 13, Anders and two friends took a catamaran 30 miles off the coast of Grand Isle to go deep-sea spear-fishing near an oil rig.

Anders was an experienced diver and had been fishing for years with his buddy Darryl Couvillion of Belle Chasse and catamaran captain William Wall of Baton Rouge.

On his third trip down into the rig structure, Anders speared a particularly feisty grouper.

He began to ascend toward the boat's deck, where his ice chest was, cradling the fish under his left arm, pulling through the water with his right arm and paddling upward with his legs.

He paused and rested 15 feet below the surface to let his body decompress, to purge potentially fatal nitrogen that builds up in the bloodstream during deep-water dives.

Anders grabbed a steel wire on the rig for support as he waited. But the grouper continued squirming on the tether of his spear gun, becoming more and more difficult to control with one hand.

Anders let go of the rig to wrest the grouper back under his control.

"That was my mistake," Anders said.

A current ripped him from the rig, and before he knew it, he was 300 yards away, Coast Guard Lt. Russ Hall said.

Anders is well acquainted with tricky ocean currents, but the harder he kicked through the Gulf's 3- to 4-foot seas, the farther he found himself from the rig.

Anders screamed toward Couvillion and Wall. But the winds drowned out his calls.

He didn't want to fight the current. He also didn't want to tread water for hours, waiting for a rescue helicopter.

He saw a tiny speck on the horizon: another rig, eight miles away. In his second life-saving decision, Anders decided to swim toward it.

He began rhythmically kicking and breathing, kicking and breathing, careful to make sure he didn't cramp up.

His goal: to get close enough to the rig to scream for help.

It was 1:15 p.m., 45 minutes past the time Anders was supposed to surface and meet Couvillion and Wall on the deck of the catamaran.

Couvillion panicked. Maybe his buddy had become tangled in something on the Gulf's floor.

He and Wall radioed the Coast Guard, then Couvillion suited up and dove into the water. He combed the ocean floor for three hours, searching for any sign of Anders.

But he found nothing. His tank ran out of air.

Couvillion surfaced and climbed aboard the catamaran. He called his wife.

"John has been missing for hours," he told her frantically. "A Coast Guard helicopter is searching for him, but there's no sign of him."

Couvillion's wife told him to take a minute to pray. He kneeled on the deck, his phone pressed up against his ear, and listened to his wife recite a prayer for Anders.

"Keep the faith," she told him before they hung up.

"But I didn't," Couvillion said. "I thought he was dead. How was I going to tell Stephanie (his wife) that her husband wasn't coming back home?"

Fifteen minutes after Couvillion talked to his wife, the radio aboard the catamaran crackled.

"Man overboard," a voice said.

The call was from a ship called the Deep Seas Discoverer. A Coast Guard rescue helicopter had spotted a man in the water, and the ship's crew was sending out a small motorboat, thinking it was one of their own.

Was it Anders? Couvillion wondered.

He hurried to the radio and broadcast a question to the Coast Guard: "Is the guy wearing a black bodysuit and a pink tank? And is he alive?"

Silence.

Couvillion again broadcast his question: "Is the guy wearing a black bodysuit and a pink tank? Is he alive?"

The Coast Guard answered: "Yes. He's in a black bodysuit with a pink air tank. And yes, he is alive."

Couvillion's heart leapt.

Couvillion and Wall sped off to find Anders, who had been taken to another oil rig to be examined. There, Anders said he gazed at them with tired but relieved eyes. His friends couldn't believe he was alive.

"We hugged in that, 'I'm glad to see your breathing carcass is still alive' kind of way," Anders joked.

The Coast Guard later determined that Anders swam at least eight miles in four hours.

"His wetsuit provided some protection from the elements, but he was in danger," Hall said.

Anders' legs didn't cramp until he stopped to tread water near the end of his ordeal. But by that time, he realized the nearby ship's crew had spotted him, and that help would come.

Less than a day later, Anders was home in New Orleans with his wife, Stephanie, who is five months pregnant.

Sizzling on the grill: a fish he had managed to haul into the boat before he got lost at sea.

(Ramon Antonio Vargas is a staff writer for The Times-Picayune of New Orleans. He can be reached at rvargas(at)timespicayune.com.)