When the incident occurred, Rainer, along with a team of divers, was filming sardines near Port Elizabeth, east of Cape Town.
Like Jonah, or Pinocchio, Schimpf had seen the inside of a whale's mouth and lived to tell the tale.
"The next moment it got dark, and I felt pressure on my hip".
"I don't think I had a "whale" of a time, but I have the inside knowledge of what a whale is like", Schmipf added. " Grim but ultimately true".
"Suddenly, dolphins shot out of the water, a white spray came out and then a whale appeared and grabbed him!"
Mr Schimpf speaks about what happened while he was inside the whale's mouth. The whale scooped him up in its jaws, but quickly realized he was too big to swallow.
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Schimpf said that it was an "interesting experience for him, but nothing he would ever want to do again".
"Whales are no man-eaters - so this was really an accident, they are gentle giants", Schimpf said.
The experienced diver explained how, at the moment he was grabbed by the enormous fish, he held his breath, fearful that the huge beast would drag him down to the depths. When a mammoth marine creature like a Bryde's whale - which is usually around 14 or 15 metres long (45 or 50 feet) - opens its mouth to feed, it engulfs whatever is in its way. As part of the baleen whale family, Bryde's whales have a relatively small esophagus - smaller than the size of a basketball - suited to eat small prey like plankton, krill and sardines, but not something as large as a human. It was no fault of the whale.
Bryde's Whale is found in all oceans in temperate and tropical latitudes.
"Nothing can actually prepare you for the event when you end up inside the whale - it's pure instinct", he said.
Meanwhile, a pod of killer whales with distinctive round faces has fuelled speculation among scientists of a new species.