Astonishing video shows a 51-year-old diver nearly getting swallowed by a whale, as he was swimming off the coast of South Africa.

Diver Rainer Schimpf found himself in the life-or-death situation while he and several of his friends were documenting a group of sardines near Port Elizabeth, South Africa.

“It happened extremely fast … I’m sure it was a surprise for the whale as well,” he told ABC News.

“It got dark and I felt some pressure on my hip. And once I felt the pressure, I instantly knew that a whale had grabbed me,” he recalled.

Only Schimpf’s wetsuit separated his flesh from the whale’s jaws. He eventually freed himself after managing to push away from the whale.

“I became the inside man -- suddenly, inside of a whale,” he said. “I don’t think I had a whale of a time … I now have the inside knowledge of whale which nobody else has.”