Off-duty lifeguards having a natter on the beach saved the lives of four beachgoers stuck in a rip at Hot Water Beach.

A dad who was swept out to sea trying to save his wife and daughter came frighteningly close to becoming a bleak statistic at a beach already known for drownings.

Four Hot Water Beach lifeguards had finished packing up and were milling about on Sunday when they heard beachgoers yelling.

About 250 metres from shore was a man frantically waving his arms, says Hot Water Beach Lifeguard Service liaison Sandi Lowe.

He'd swum after his wife and daughter who were struggling against a rip.

"But he found himself in great difficulty."

Two young off-duty volunteers, Chloe Hines-Senior and Georgie Hood, stripped down to their togs and swam out to the struggling bunch with fins and rescue tubes.

Lowe and another senior lifeguard Stacey Semmens waited on shore, readying themselves to get the boat and other gear - locked up about a kilometre down the road - if needed.

Hine-Senior and Hood raced out to the group, but the swimmers - especially the dad - were growing tired.

"He was just starting to sink as [the lifeguards] got out to him.

"It could have been awful ... It would have been a fatality."

While out at sea, they spotted another woman struggling against the same rip.

The pair of lifeguards swam her and the man to shore before heading straight back into the water to the woman and daughter, who were getting sucked further and further out to sea.

"[The lifeguards] had just had a huge day at the beach lifeguarding as well," says Lowe. "In normal circumstance we would have gone the hour before.

"[The group] realised that at least one of them would have been a drowning statistic."

While it's human instinct to try and save a loved one, rescuers often find themselves in the most trouble, Lowe said.

In October, a granddad died trying to save two girls at the same beach.

And in this case, the sea looked deceivingly void of rips.

But it's a timely reminder for swimmers to respect the sea, says Lowe.

"We have 'danger' and 'no swimming signs' and, honestly, people hang their towels over them."