An Australian abalone diver told rescuers he was partly swallowed head-first by a Great White Shark but managed to fight his way free, suffering a broken nose and bite marks around the chest.

Diver Eric Nerhus, 41, was underwater with his 25-year-old son and other divers off Cape Howe, near Eden on Australia's southeast coast, when the three-metre shark attacked.

Rescuers earlier mistakenly reported his age as 25.

"He stated that he was head-first into the shark," a spokesman for Snowy Hydro SouthCare rescue service said after airlifting the diver to hospital.

"When he came to us he was conscious and alert but had a broken nose and lacerations to both sides of his torso and chest - bite marks all the way around," the spokesman said.

Mr Nerhus told fellow divers he didn't see the shark coming as the water was so dirty that visibility was severely limited.

"It was black. He didn't see it coming, but he felt the bite and then started getting shaken, and that's when he knew he was in the mouth of the shark," said local diver Michael Mashado.

The shark bit Mr Nerhus around the head first, crushing his face mask and breaking his nose, fellow diver and friend Dennis Luobikis said.

"He was actually bitten by the head... the shark swallowed his head," said Mr Luobikis, adding a second bite by the shark saw it clench its jaw around Mr Nerhus's torso.

"The brunt of the bite was taken by his lead-weight vest. Its all over your torso. Eric said to me at the wharf that his weight vest saved him," he said.

Abalone divers spend sometimes six to eight hours underwater and use lead weight vests, not lead belts, to stay down. The vests spread the lead weight across the body, minimising back strain.

Mr Nerhus fought frantically to free himself from the shark's jaws and was eventually pulled back aboard his boat by his son.

"He pushed his abalone chisel into its head while it was biting and it let him go and swam away," said Mr Luobikis.

Mr Luobikis said it was a miracle his friend had lived.

"Eric is a tough boy, he's super fit. But I would say that would test anyone's resolve, being a fish lunch," he said.

Attacks by Great White Sharks are usually fatal because of the massive size of the predators, which breed in Australia's cold southern waters, and the sheer force of their bites.

Sharks, including Great Whites, are protected in Australia.

Australia has had a number of shark attacks in the past year.