Some speculated it had been pulled from the lake and moved by truck, never to be seen again.

The plot thickened in 1995, when divers from Bateaux Below, an underwater archaeology group dedicated to finding and preserving sunken and historic boats, discovered the long-missing yellow submarine.

Bob Benway remembers when he and others from Bateaux Below found it.

"To me it's the Holy Grail of Lake George. It's always been my personal Holy Grail."

Word of the discovery was the top story on the evening news, but it was missing two key elements---the who and the why.

Now we know both.

WEB EXTRA: 1995 NewsChannel 13 story on Baby Whale missing submarine

"The intent was not to steal the sub. It was to hold it hostage," said Bill Thomas of Warrensburg, who 60 years later is telling the story publicly.

Thomas says he and his brother, John, were both just teenagers, when they took it and sunk it as revenge because John had paid one of the owners of the sub to teach him to scuba dive, but he never did.

So they used a 17-foot motorboat to tow it out into deep water and John smashed the porthole with a wrench.

"And climbed up the ladder, got on top of the hatch and jumped, and just as soon as he jumped, the sub popped up like a tip-up, hit his foot, he fell into the boat, never saw the sub go down," said Thomas.

John passed away a few years back. Bill's been living with the guilt for 60 years. Until now.

"So coming to the 60th anniversary, I said, 'It's time. It's time to get this albatross off my neck.'"

Thomas says he didn't want to be there, but he's thankful he was, because he was able to convince his brother to break the porthole from the outside. He says if he'd done it from the inside, his brother would have gone down with the sub.

Benway says Bateaux Below placed an underwater sign near the sunken sub, but it's the organization's long-standing policy to not disclose the exact whereabouts of its discoveries.