Jet ski crew crucial to Fanning's survival

A shark expert has praised the quick response of a jet ski crew, saying they helped save Aussie surfer Mick Fanning from becoming shark bait.

Fanning's miraculous escape has captured worldwide attention after a large shark stalked, then attacked him during the final of the J-Bay Open at South Africa's Jeffreys Bay.

The 34-year-old escaped without a scratch but spent a terrifying 40 seconds in the water after the shark approached him from behind, apparently becoming tangled in the surfer's leg rope.

Mark Meekan, from the Australian Institute of Marine Science, said the attack bore all the hallmarks of the great white's hunting style, and the quick response of the jet ski crew that rescued him could not be underestimated.

"The white shark is an ambush predator so they will take a bite, retreat off and wait for the prey to die," he said.

"So there is an opportunity in that window for people to be rescued."

Dr Meekan said Fanning had done everything possible to scare the shark off, with the surfer later telling reporters he punched the predator in the back during his struggle for life.

"People say (punching sharks in) the nose and eye can work," he said.

"They do have a lot of sensory systems around the head but they are very tough animals so whether or not that is likely to have an effect - the jury is still out."