The critical Triple Zero (000) call made by 13-year-old Austin Appelbee to alert authorities after he and his family were swept out to sea south of Perth has been released.

“Mum said go get help, because she said we were in massive trouble,” the teenager tells the operator in the call.

In a calm voice, Austin explains to the operator his family are “kilometres out to sea” and his mother has asked him to fetch help.

A boy sits in a chair listening intently

Austin Appelbee sat down for an interview about his experience days later. (ABC News: Briana Shepherd)

“We got took out to sea and we got lost out there and now … I don’t know what time it was but it was a long time ago,” he says in the recording released by police on Wednesday.

“We couldn’t get back to shore and Mum told me to go back to get help.

“I haven’t seen them since … I think we need a helicopter.”

Woman with three children standing in bushland

Austin (right) with his brother Beau, mother Joanne and sister Grace (left to right).  (ABC News: Briana Shepherd)

The teenager, who had just emerged from the ocean at Geographe Bay in WA’s South West, after a four-hour swim, told the operator he feared for his family’s safety.

“So mum is out there with kids as well, is that right?” the operator asks.

“Yeah and I don’t know what their condition is right now and I’m really scared,” Austin tells her.

Austin Appelbee seated outdoors, speaking in an interview.

13-year-old Austin Appelbee recounts his heroic four-hour swim through rough seas to help his family.

The family were swept out to sea last month after renting paddleboards and a kayak from their resort in Broadwater near Busselton, about 250km south of Perth.

When no-one came to rescue them, Austin’s mother Joanne Appelbee asked her eldest son to swim back to shore to get help while she tried to calm her other children, 12-year-old Beau and 8-year-old Grace, who were clinging to paddleboards.

Kayaks line the shore of a beach

Kayaks line the shore of Quindalup beach, where Austin’s family set off from. (ABC News: Bridget McArthur)

International headlines

Austin’s remarkable swim had made news around the world, with rescuers praising his “superhuman” efforts to save his family.

The family was eventually rescued after an estimated 10 hours in the ocean, after Austin ran 2km from the beach where he came ashore to find his mother’s phone so he could make the Triple Zero call.

Austin Appelbee swam for hours to save his family

How Austin Appelbee saved his family in a miracle ocean rescue.

The teenager’s voice remains steady in the call, as he describes the kayak he abandoned in the ocean before swimming to shore, and urges the operator to send help.

He then goes on to describe the physical toll his epic swim has taken.

“I think I need an ambulance because I think I have hypothermia,” he said.

“I’m extremely tired. I have heat stroke and I feel like about to pass out, I’m very dizzy.”

All four family members were treated overnight at Busselton Health Campus and released the following day, with Austin needing a wheelchair and crutches to help walk for several days afterwards because of the strain on his legs.

A map showing a rescue off Geographe Bay

A map showing roughly where the family was found in Geographe Bay, and the wind speed. (ABC News)

Local police have praised the Austin’s ability to keep a cool head after his marathon swim.

Dunsborough Police Acting Sergeant Andrew McDonnell said the teenager’s ability to clearly provide key information was critical to the rescue of his family.

“After his 4-kilometre swim across the bay, it struck us all how articulate, calm and collected he was,”  Acting Sergeant McDonnell said.

“It was incredible to listen to.”