A 13-year-old Australian boy is being praised for completing a heroic four-hour swim to save his mother and siblings from being swept out to sea in Western Australia, state police said in a statement on Monday.

The family was on vacation in Quindalup, on Geographe Bay, about 250 kilometres south of Perth, on Friday, when strong winds blew their inflatable paddleboards and a kayak offshore.

Austin Appelbee attempted to paddle to shore in his kayak before it began taking on water, so he swam four hours back to the beach in fading daylight, where he alerted authorities that his two siblings, Beau, Grace and mother, Joanne, were stranded.

Naturaliste Marine Rescue commander Paul Bresland told the Australian Broadcasting Corporation (ABC) that the boy’s 47-year-old mother, 12-year-old brother and eight-year-old sister were found at about 8:30 p.m. on Friday, clinging to a paddleboard about 14 kilometres offshore.

“He swam in, he reckons, the first two hours with a life jacket on,” he said.

“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,” Bresland told the Australian outlet.

Naturaliste Volunteer Marine Rescue Group, which aided in the rescue effort, told the BBC, “The bravery, strength and courage shown by this family were extraordinary, especially the young fella who swam four kilometres to raise the alarm.”

Once he reached land, a multi-agency effort was launched to rescue the boy’s family members, comprising WA Water Police, local volunteers and a helicopter.

A volunteer marine rescue vessel was directed to their location, and all three were successfully rescued and returned to shore, police confirmed.

Insp. James Bradley said the incident should serve as a reminder of how quickly conditions at sea can shift and of the importance of taking safety precautions.

“This incident is a reminder that ocean conditions can change rapidly. Thankfully, all three people were wearing lifejackets, which contributed to their survival,” he said. “The actions of the 13-year-old boy cannot be praised highly enough — his determination and courage ultimately saved the lives of his mother and siblings.”

Bresland said the boy’s description of the colour of the kayak and paddleboards was crucial in directing a successful search effort.

“Within an hour, we found the kayak,” Bradley told ABC.

He said the family had kept themselves afloat in rough seas for hours before they were rescued, and that the mother managed to keep the other two children safe with the help of the paddleboard.

“Physically, she just said, ‘I’m struggling, I can’t,’ but she just said they’re looking her in the eye, and she just kept going and kept them together,” Bresland added.

The trio were assessed by St John WA paramedics before being conveyed to Busselton Health Campus for medical assessment.

ABC said the Appelbee family was discharged from the hospital over the weekend and visited the rescue crews who saved their lives to thank them for their efforts.