A surfer who punched a great white shark during a frenzied attack on NSW's northern coast had his hand almost severed.

Craig Ison, 51, underwent microsurgery in the Gold Coast University Hospital on Sunday to reattach tendons and to save him from losing his hand.

Craig Ison, who was attacked by a great white shark at Evans Head on the NSW North Coast. Credit:Channel Nine News

The former champion boxer punched the shark twice as it dragged him off his board at Evans Head's Main Beach and bit him on the left leg and arm.

He was on his daily surf at 6am on Friday with his friend Geoff Hill, who saw the attack and described it as "like watching a Mick Fanning replay".