Teen swims 4 hours to save family lost at sea off Australia

Rescuers praised a teenage boy's "superhuman" survival instincts after he swam four hours through choppy waters off Australia to find help for his family.

The 13-year-old boy swam four kilometres (2.5 miles) back to shore to raise the alarm after his mother and two younger siblings were swept out to sea while kayaking and paddleboarding near the Western Australian tourist town of Quindalup.

Marine rescue volunteer Paul Bresland said the teenager's four-hour swim saved his family, who were eventually found clinging to a paddleboard in the open ocean. 

Following this, he swam for fours hours and told a rescue team about what happened to his family.

Local media quoted Bresland as saying the mum was found with her son, 12, and her daughter, eight, about 14 kilometres offshore, holding onto a paddleboard.

"He swam, he reckons, the first two hours with a life jacket on," Bresland told national broadcaster ABC. 

"And the brave fella thought he's not going to make it with a life jacket on, so he ditched it, and he swam the next two hours without a life jacket.

"I thought, mate, that is incredible," said Bresland, describing the boy's efforts as "superhuman".

Australian TV channel ABC reported the boy and his family were on holiday 250 km south of Perth at Quindalup on Friday evening when strong winds pushed their inflatable paddleboards and kayak out to sea.

The boy then attempted to paddle back to shore, however his kayak began to take on water in the choppy sea.

Police inspector James Bradley said the boy's actions "cannot be praised highly enough". 

"His determination and courage ultimately saved the lives of his mother and siblings," he told the ABC.

A search and rescue operation spanning multiple agencies began after the boy swam to shore.

This included WA Water Police, Western Australia's Rescue Helicopter, and local marine rescue volunteers.

Bresland said the boy was able to provide a detailed description of both the kayak and paddleboards, which led authorities to find the family "within an hour".

"Thankfully, all three people were wearing life jackets, which contributed to their survival," he said.

When the rescue teams found the family, they were pulled from the water and returned to shore in a volunteer marine rescue vessel.

Bresland said the mother's actions in keeping the children alive made her "an absolute hero as well".

"To keep those two children together and not give up is absolutely incredible."

The mother and two children were then checked over by paramedics and were then sent to the nearby Busselton Health Campus.

ABC reported the family were discharged over the following weekend, and had visited rescue teams to give their thanks.