A surf lifesaver doing a random check of a known risk spot managed to save a 60-year-old swimmer from drowning in rough seas Friday afternoon.

Batemans Bay SLSC duty officer Anthony Bellette was doing a spot check at MacKenzies Beach, south of Batemans Bay, about 2.45pm when he noticed the man in trouble in the surf.

Mr Bellette swam out with a tube and kept the Sydney man afloat, but the rough conditions made it impossible to swim him back to shore.

The Westpac helicopter was called in and winched both men to safety.

Two other swimmers were also rescued and taken to shore.

The Westpac Helicopter was then called to an island off Narawallee Beach, near Ulladulla, where two people were stranded.

They were flown back to the beach to be checked by ambulance paramedics.

Then lifesaving services, including a jet sit, inflatable boat and rescue helicopter, were called to the Merimbula Bar, after a vessel hit a sandbar, throwing three people into the water.

All were safely accounted for.

It was a busy day on the Far South Coast. Earlier on Friday three swimmers were reported in trouble at the Pambula River mouth.

They were rescued without incident.

Lifesavers are repeating their warnings of dangerous surf this weekend and are pleading with holidaymakers to only swim at patrolled beaches and take extra care on the water.