Police said the man went to help his nine-year-old daughter who got caught in a rip at the southern end of Surf Beach, Batemans Bay at about 12.45pm.

Acting inspector Tim Winkelman of Batemans Bay Police said members of the public managed to help the young girl, however, her father was swept to sea.

"Some members of the public assisted his daughter in the water, but then he was taken further out to sea," Mr Winkelman said.

Batemans Bay Marine Rescue and Batemans Bay surf lifesavers commenced a search.

Far South Coast director of lifesaving, Cheryl McCarthy, said one lifesaver swam out with a rescue tube and another paddled out on a surf ski.

At about 1.20pm, the man was located about 300 metres offshore by the lifesaver on the surf ski.

"They were able to reach the man and perform CPR on him in the water," Ms McCarthy said.

Both lifesavers used the surf ski as a platform to support their CPR efforts.

A Marine Rescue vessel arrived to assist. The unconscious man was lifted onto the boat.

Ms McCarthy said lifesavers continued CPR with the Marine Rescue crew as they returned to the beach.

NSW Ambulance was at the scene. The man was unable to be revived. His daughter was taken to Batemans Bay Hospital in a stable condition.

Ms McCarthy said there was a north-east swell, with no wind during the rescue. She said it was "tricky to negotiate the break" and there was a "strong rip" at the southern end of the beach.

She encouraged people to be aware of the conditions before going into the water.

"Take a good look at conditions before you or your family go into the water," Ms McCarthy said.