© FlickerThe victim described the shark as a bull shark
Steven Fogarty was snorkelling at Windang near the entrance to Lake Illawarra when the shark bit him on the leg, leaving 40 puncture wounds.
He described the shark as a bull shark and said he punched the shark until it let go.
Mr Fogarty was released from hospital this afternoon.
Aerial Patrol spokesman Harry Mitchell says a search of the lake and nearby beaches found no sharks, despite recent sightings.
"We launched the aircraft over the top of the area, within 10 minutes of the alleged attack, and we carried out a surveillance east of the bridge through the channel there and in other parts of the lake as well, with no evidence of any shark activity," he said.
© ABCThe man was attacked at Windang near the entrance to Lake Illawarra
A 31-year-old Brisbane man was surfing with three friends when a shark bit him on the leg at Fingal Beach on the north coast of NSW yesterday.
Thirteen-year-old Hannah Mighall was attacked by a five-metre white pointer shark at Bailey's Rocks yesterday afternoon.
Beach warning
The spate of shark attacks across Australia so far this summer has prompted New South Wales far south coast lifesavers to warn swimmers to be vigilant.
Far south coast director of lifesaving Mark McLeay says there have only been a few sightings in the region this summer, but people need to be alert.
"One thing I want everyone to realise is that if you do see something that could be a shark, raise the alarm," he said.
"It is a lot better to be prepared than to get attacked."
The situation is rather peculiar and pretty scary indeed. Shark attacks are being reported daily right now - and kinda keep on coming...
There are several schools of thought at the moment as to the true causes.
Some are claiming that it is overfishing that caused the sharks to be hungry and come to the beaches to feed. In case you were wondering, these predators don't mind a bit of human either.
Others deny that and claim that this is all normal, nothing to be concerned about (forget the people that got hurt), normal breeding behaviour, etc.
In the meantime, the sharks care not for any of that and continue to attack swimmers not just on the open beaches - but also in inland canals.
The hysteria is brewing.
Personally, I don't think that this is normal at all, man. The last spike I can recall was around Tsunami 2004. There was a lot of weird animal behaviour around that time period, too.
Let's wait and see...
"La Nina" effect may be behind shark attacks