The search is resuming for the experienced abalone diver who was last night taken by two great white sharks off the South Australian coast. Authorities believe two great whites dragged unoficially identified Esperance resident Peter Clarkson under and took his body out to sea in Coffin Bay on the Eyre Peninsula.

The ferocity of the attack was witnessed by the skipper of the abalone fishing boat who is suffering from "significant shock" and had been unable to give many details about the attack.

He told ambulance officers: "I saw the beast come up and take him. There's no way he could have survived," according to a News Ltd report.

It has emerged that Mr Clarkson detailed a previous encounter with a great white in a testimonial for the Shark Shield protection device. The diver had survived a brush with a great white only last August.

Senior Constable Paul Noble said police, the State Emergency Service and local fisheries officers were searching for the missing diver in rough and wet weather.

"It will certainly involve the aircraft wing and they will conduct a ground search for the surrounding beaches," he said.

A close friend and abalone diver, Mark Payne, said people at Esperance were devastated by news of Mr Clarkson's death.

"I found out yesterday afternoon and it was quite a shock."

"I just mentioned it to a couple of local people who are good friends of Peter and the shock's settled in the town at the moment, especially amongst a few of the guys that are into shell diving and abalone diving."

There has been no trace of the diver or his equipment and his identity has not been officially released at this stage.