"I was trying to get footage with a rinky-dink camera. I looked down, because I was exerting myself a lot, and I think the tanks weren't fastened properly, and I had, like 40 pounds of pressure," the Daily Express quoted him as saying in the new issue of Rolling Stone magazine.
The actor was too deep to simply swim to the surface, and thus he took one deep breath and rejoined his diving group who shared oxygen with the star.
He admits there was a moment when his life flashed before him.
"All you think about at that moment is, like, Get me the hell out of this situation," he said.