The 29-year-old man was reported to be in stable condition Saturday at a hospital in Newcastle, the Port Macquarie News reported. He was flown by helicopter from Diamond Head in New South Wales after the attack.
The attacker was believed to be a bull shark, an aggressive shallow-water species.
The attack occurred about 10 minutes after a pod of dolphins swam through the area. Senior Police Constable Chris Rowley said the man hit the shark on the nose several times in an attempt to repel it.
"I don't know what the right way to turn the attack back on a shark is, but it appears punching it in the nose is a pretty good trick," Rowley said. "He is a pretty tough rooster."