Blue whale capsizes boat off California coast

Two crew members were thrown into the sea

Dale Frink clings on before he is flung into the water (YouTube)

This is the terrifying moment a blue whale overturned a boat sailing off the coast of San Diego in California.

Scroll down for video

A wildlife photographer caught the action on his camera as he was flipped into the waters about 12 miles from shore.

Dale Frink is seen frantically attempting to keep his balance as the boat rocks, before crying out: "Oh my god!"

Frink and the boat's captain, Cici Sayers, were both thrown overboard in the incident, which saw the marine mammal surface and strike the underbelly of the 23-foot vessel.

The pair had been watching a group of blue whales from a perceived safe distance when the giant approached, according to CBS affiliate KFMB-TV.

"It just came down. I literally thought it was going to take a bite out of the back of boat," said Sayer.

A nearby boat witnessed the scene and alerted the US Coast Guard.

Mr Frink said: "I said to myself: 'Dale, just do what you can to keep yourself safe, but if you can save that camera, save the camera!'".

And by the looks of this footage, it's a good job he did.