Powerful surf conditions caused chaos on the coast with multiple swimmers getting into difficulty at beaches up and down the NSW coast.

Despite the challenging swell the crowds were undeterred with the heat prompting many to flock to the beach.

There are serious concerns for a 22-year-old swimmer who went missing after getting caught in a rip at Valla Beach on the North Coast. That search will resume on Sunday with lifesaving assets to assist in the operation led by NSW Police.

Elsewhere a 15-year-old is recovering in hospital after being pulled from the water by lifesavers at Kiama Beach at around 3pm.

Two swimmers were rescued by surfers at Turimetta Beach, North Narrabeen, while a surfer was transported to hospital after swallowing water in an incident at South Narrabeen.

At Avoca Beach on the Central Coast there was a mass rescue carried out by lifesavers who utilised a jet ski and an inflatable rescue boat to pull six people from a rip current.

A hazardous surf warning remains in place for at least the next 24 hours with swells peaking over three metres expected along much of the NSW coast.

Beaches between the waters of the Lower North Coast through to the Queensland border in particular are likely to experience larger swells, but lifesavers are urging everyone regardless of where they are swimming to not get complacent.

“Please take note of the safety warnings and if you have any doubt whatsoever about your ability to handle the water it’s better not to go in,” said NSW Lifesaving Manage Matt du Plessis.

“The red and yellow flags are there for a reason and we urge you to make that effort to swim there. We’ve had several instances of people being pulled from rips over summer so please take those few extra seconds to evaluate the conditions and to talk to the lifesaver or lifeguard on duty,” Mr du Plessis said.