Only 60 miles off the coast of New Jersey, in 230 feet of dark, frigid water, lays the twisted hulk of World War II U-boat — a German submarine that once prowled the American coastline.
Decades after the war, a team of daring divers found the wreck. They didn't do it in the safety of a mini-sub like the one that found the Titanic.
As 60 Minutes II correspondent Mika Brzezinski learns, they risked their lives to swim down to it with just the air tanks on their backs.
They discovered a mystery at the bottom of the sea: the wreck was in a place where wartime naval records said no German sub had sailed or sank.
Solving that mystery proved deadly for three of the divers who lost their lives exploring the wreck.
But two other divers, John Chatterton and Richie Kohler, just wouldn't quit. They call themselves deep-wreck divers — extreme adventurers who dive to depths even the most experienced scuba diver would fear to go.
"I identify myself as wreck-diver," Kohler says. "The majority of our friends are wreck-divers, and they understand us. There are people outside that circle, like you, who look at us and think we're insane."
We met Chatterton and Kohler — the one with the beard — where their story began: on a dock in the small town of Brielle on the New Jersey shore.
The small fraternity of divers who like to risk their lives in their spare time gather here. It's no place for average scuba divers.
"You know, putting a tank on their back, jumping into 30 feet of water, that's a hobby," says Chatterton. "What we do is much more of a lifestyle."
Writer Robert Kurson told the story of these underwater explorers — and how their obsession led them to solve a 60-year-old mystery — in the best-seller "Shadow Divers."
To get a first-hand look at the world of those shadow divers, Brzezinski asked Chatterton and Kohler to take her out to sea, back to the place where they spent six years searching for answers.
Chatterton and a few other divers left this same crowded harbor one September morning back in 1991. They were checking out a tip from a fisherman who had found some kind of wreck on his sonar, 60 miles out to sea.