Plea from frustrated lifeguards as swimmers swarm beaches, need rescuing

The iconic red and yellow flags were out at a very busy Bar Beach on December 28 and the speaker was blaring with warnings.

One beachgoer told the Newcastle Herald some swimmers were brought back to shore, and lifesavers urged the crowd to cooperate.

The witness said swimmers were warned the beach could be forced to close if people didn't follow the rules.

Surf Life Saving NSW chief executive Steven Pearce said there was a degree of frustration among crews.

"If people don't listen to the messages, it's up to our lifesavers and lifeguards to go in and rescue them," he said.

"We would never close a beach in frustration, however, we would close a beach where we thought it was too dangerous because we didn't have enough resources there to look after the amount of people in the water."

Mr Pearce urged all swimmers to only enter the water between the flags, and swim during patrol hours.

Multiple rip currents were spotted between Merewether and Bar beaches on Thursday.

It comes amid a horror start to the summer season in the Hunter and across the state.

Four people have drowned on the NSW east coast since Christmas Day, including one man at Stockton Beach at Anna Bay on Wednesday afternoon.

A woman he was swimming with remains in a serious but stable condition in John Hunter Hospital.

Four people - including a one-year-old baby - were pulled from the water at the Central Coast's notorious Frazer Beach that evening.

The temperature at Nobbys weather station was 29.7 degrees at 11.30am on Thursday, according to the Bureau of Meteorology.

"We know we still have an incredibly hot summer in front of us," Mr Pearce said.

Those that make the decision to swim at unpatrolled beaches should be confident in their ability, always call triple zero immediately if they notice someone in trouble, and should have a flotation device - like an esky, pool noodle or soccer ball - handy at all times.