A diver who was almost swallowed head first by a huge shark said Wednesday he survived by poking the animal in the eye and credited the lead-lined vest he was wearing as saving him from being chomped in half.

Abalone diver Eric Nerhus, 41, described Tuesday's terrifying attack by a shark estimated by witnesses to be 10 feet long off the fishing town of Eden, about 250 miles south of Sydney.

Nerhus was working with his son and other divers collecting the shellfish when the shark struck from nowhere at about 26 feet below the surface, grabbing him by the head and shoulders, he said.

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"Half my body was in its mouth," Nerhus told Australian television's Nine Network.

Nerhus said he fought desperately.

"I felt down to the eye socket with my two fingers and poked them into the socket," he said. "The shark reacted by opening its mouth and I just tried to wriggle out."

"It was still trying to bite me. It crushed my goggles into my nose and they fell into its mouth."

He said he managed to finally escape the shark's jaws after jabbing at its eye with a chisel he used to chip abalone from rocks, and was still holding despite the attack.

Nerhus, who estimated he spent two minutes inside the shark's mouth, said his chest was protected from the shark's rows of teeth by a lead-lined vest used to weight him down in the water.

As he swam to the surface in a cloud of his own blood, Nerhus said he could still see the shark and feared it would attack again.

"It was just circling around my flippers, round and round in tight circles," he said. "The big round black eye, five inches wide, was staring straight into my face with just not one hint of fear, of any boat, or any human, or any other animal in the sea.

He was helped into his boat by his son, and rushed to hospital, where he was being treated for severe cuts to his head, torso and left arm.

An expert said the shark that attacked Nerhus probably mistook him for a seal, which are common in waters off southeastern Australia and attract sharks to near the coast.

Grant Willis of the Sydney Aquarium said that after the shark bit Nerhus, it probably realized "he didn't taste anything like a seal — sort of a bit bony and horrible and nothing like a seal at all — so possibly it spat back out."

"He's had a run-in with one of the ocean's most formidable predators and he's lived to tell the story," Willis said. "He's a very, very lucky man."

Scientists say there are an average of 15 shark attacks a year in Australian waters — one of the highest rates in the world — and on average just over 1 per year are fatal.