A 12-year-old boy and his father, who was in his 50s and weighed more than 100kg, were caught in a rip at Broulee Beach just after 5pm.

Broulee lifesavers said conditions were potentially life threatening.

The father was struggling to get to shore and keep his son afloat on his body board.

Two lifesavers were training nearby and noticed the father and son in trouble. The lifesavers, Billy Hughes-Tweedie and Ben McKay, immediately paddled to the pair and put both father and son on their boards.

Broulee lifesaving trainer Darren Phillips said the two lifesavers had not hesitated in paddling into the dangerous surf.

''Ben saw the incident unfold and immediately paddled to the boy and pulled him onto his board,'' Mr Phillips said.

''Meanwhile, Billy pulled his father onto the board and really handled himself well taking on the large waves.''

Mr Phillips said the man had little idea of how dangerous the surf was and panicked when he realised he was caught.

The incident has sparked warnings for swimmers to stay at patrolled locations during normal patrol hours.

The region experienced one of its worst seasons on record last year with eight people drowning, nearly a quarter of the total for NSW.