A Western Australian family holiday has become a story of courage, grit and love after a fearless 13-year-old boy swam for four relentless hours through rough seas to save his mum and younger siblings.

Austin Appelbee is being hailed as a hero after an ordeal off the south-west coast that could have ended very differently. Swept out to sea near Quindalup last Friday, Austin and his family drifted 14 kilometres from shore when worsening wind and ocean conditions overwhelmed their hired kayaks and paddleboards.

As oars were lost and the distance from land grew frighteningly wide, Austin’s mother Joanne made an almost unthinkable decision. With three children to care for and no way to get everyone back, she sent her eldest – the strongest swimmer – toward shore to raise the alarm.

What followed was nothing short of astonishing.

Austin first attempted the journey on an inflatable kayak, but it began taking on water. With waves building and time slipping away, he abandoned it. His life jacket, too, became a hindrance in the heavy swell. Alone in open water, the teenager struck out for land.

For four hours he swam, switching between breaststroke, freestyle and survival backstroke, pushing through exhaustion and fear by focusing on one simple mantra: “Just keep swimming”.

When he finally reached the beach, Austin collapsed in the sand. Then, summoning one last burst of determination, he ran two kilometres to find help, using his mother’s phone to call emergency services.

By nightfall, a police helicopter located Joanne and Austin’s siblings – Beau, 12, and Grace, 8 – clinging to a paddleboard, all wearing life jackets. They were cold, shivering and exhausted, but alive.

“The actions of the 13-year-old boy cannot be praised highly enough,” WA Police Inspector James Bradley told reporters. “His determination and courage ultimately saved the lives of his mother and siblings.”

Joanne said the wait was agonising as daylight faded and the ocean grew rougher, but she and the children did everything they could to stay calm. They sang, joked and tried to keep spirits up, even as the cold set in and Beau began losing sensation in his legs.

“I have three babies. All three made it. That was all that mattered,” she said.

Remarkably, none of the family required serious hospital treatment. As for Austin, he remains characteristically humble. “I didn’t think I was a hero,” he said. “I just did what I did.”