Like any doting grandmother having a moment on national television, Dorian Patrick was full of praise when asked about her grandson, the hero swimmer Austin Appelbee.

What Ms Patrick didn’t know as she spoke on Ireland’s Late Late Show about the 13-year-old’s brave swim to save his mum and siblings, was that Austin and his family were waiting backstage to surprise her.

As a guest in the audience of the popular show, which is viewed by hundreds of thousands, Ms Patrick retold the events of Austin’s headline-making adventure after the young family were swept out to sea out off the Dunsborough coast in January.

“He swam four kilometres and he ran two kilometres to save his mother and two siblings,” she told host Patrick Kielty, explaining that Austin’s mum Joanne made the agonising decision to send her eldest child off into the deep blue alone.

“They were out kayaking in Australia. The current took them out. They kept going out and out and out and there was no way back.

“So she (Joanne) had to decide to let some of them go so Austin being the oldest boy, he wanted to go, but she didn’t think he’d (be able to) go against the current because the wind and the the waves were very, very high.

“So anyway, she had to let him go because (it was) that or nothing.”

As the Irish television audience cheered, Kielty revealed the Late Late Show’s big secret — and unveiled Austin, Joanne, Beau and Grace to the sheer delight of his overwhelmed grandparents.

“We think you’ve maybe waited a bit too long for that hug,” Kielty said. “We’ve flown them home tonight. They’re here from Australia.”

As the crowd erupted and the long-haul travellers appeared on stage, Ms Patrick broke into tears and there was hugs aplenty.

The outcome of Austin’s remarkable swimming feat — having ditched his lifejacket along the way — made headlines around the world and Austin a legend in WA.

If he wasn’t already, he’s also now a hero in his family’s native Ireland.

But four months on from the rescue, the harrowing ordeal remains fresh in the minds of the family.

Fighting back tears, Ms Appelbee retold living through one of the worst decisions a parent could be forced to make.

“There was no other way of getting out of it than the decision I made, which is every mother’s nightmare. I hope that nobody else ever has to make this decision in their lives, but we’re here to tell the tale,” she said.

Austin, meanwhile, didn’t hold back on adding a bit of flare to his recollections.

He revealed that once he made it to shore and shook off his “jelly” legs, he “started running and felt like (David) Hasselhoff in that moment”.

The crowd erupted in laughter and applause, solidifying the teenager’s newfound status as an international hero.