A man who witnessed a shark attack on a surfer off Western Australia's south coast says the victim is extremely fortunate to have survived.

Michael Bedford was surfing 150 metres offshore at Conspicuous Cliff beach near Walpole yesterday when he was attacked.

The shark, believed to be a white pointer, knocked him off his board before coming back to charge him a second time.

Mr Bedford managed to scramble onto his board before a well-timed wave pushed him into shore.

His friend, Lee Cummuskey and others, used his surfboard to carry him along the beach and up a cliff to a carpark to wait for an ambulance.

They then used his leg-rope as a tourniquet to try to stem the loss of blood from a deep gash to his right knee.

Mr Cummuskey says Mr Bedford is lucky to have survived.

"Just the fact that there was people on the beach to help us, and yeah, it didn't hit an artery so he didn't lose a lot of blood, I think that was really critical too," he said.

He says it appears the shark was a white pointer.

"It did have a big white gut on it and he gave it a good whack he reckons, a good punch and that doesn't surprise me knowing Mick," he said.

"It is, I don't know what to say, it is your worst nightmare and Mick's been through it and survived so he's just really lucky."

Mr Bedford underwent surgery in Albany Regional Hospital last night where his condition is listed as stable.