Unconscious Sydney swimmer rescued

An unconscious man has been pulled out of the water at an eastern Sydney beach after he knocked his head on a sandbar while swimming.

The man, thought to be in his 30s, was not breathing and had a cut on his head when patrolling lifesavers rescued him shortly before 9am on New Year's Day, Surf Life Saving NSW says.

He regained partial consciousness after about 10 minutes of CPR and was taken to hospital where he remains in a serious condition.

"This incident highlights the importance of swimming at a patrolled location as the patient was able to receive treatment almost immediately," Surf Life Saving NSW operations manager Adam Weir said on Friday.

Volunteer lifesavers will be patrolling each weekend and public holiday until the 2015/16 season concludes on April 25.