Divers Tell Tale Of Mystery Sub

U-Who? 6-Year Search Nets Answers

(CBS)  The men didn't know what they were going to find out there. It could have been nothing.

"Oh, sure," says Chatterton. "So our plan was I was gonna go down and take a look."

Chatterton took a camera 230 feet down into the dark waters, where the shapes were eerie and unfamiliar.

"That’s when I saw the angled hatch. I went over. I looked into the hatch. I shined my light down and I could see the unmistakable shape of a torpedo. At that moment, I knew this is a submarine," he says.

Not just any submarine, but a World War II German U-boat. But which U-boat? And what was it doing off the Jersey shore?

German war footage shows a forgotten chapter of WWII: the story of German U-boats hunting — and sending to the bottom — dozens of merchant ships up and down the American coast.

American warships sank many of those U-boats. All of them were accounted for. None were missing off New Jersey.

"You know, this is my backyard. I know the local history," Chatterton said. "We know what wrecks are out there, and this thing wasn’t on the radar."

Chatterton and Kohler are local boys.

Kohler makes his living running a glass company in Trenton, N.J. He grew up in a working-class neighborhood in Brooklyn, where his father introduced him to diving. Chatterton discovered diving after serving as a combat medic in Vietnam. He says the adventure drew him to the sport. While the men call diving an adventure, others would call it danger.

"Well, there certainly is a significant amount of danger relative to my diving activities. But, you know, you have to manage that. And that’s what we do," says Chatterton.

Chatterton's video from the wreck shows just how dangerous. Pipes, wires and pieces of steel hung at crazy angles, ready to snare divers and their bulky gear.

Inside this undersea booby trap, Chatterton, Kohler and the rest of the dive team looked for something that would identify which U-boat it was. They thought it would be easy.

"Every single guy, without exception, that rolled over the side to dive the wreck thought that he was gonna be the guy to solve the mystery," says Chatterton.

They brought up dishes from the ship’s galley and the captain’s chronometer, which was used for navigation.

"In my hand, I’m holding a tangible piece of history," says Kohler.

And a fragile piece of milky glass that was part of the ship’s telegraph, which relayed commands to the engine room.