Bodysurfer Rick Shearman’s smartwatch is the reason he’s still alive.

Things took a turn for the worse after Shearman went in for a bodysurf in Byron Bay in July last year.

He was unexpectedly sucked out to sea and left stranded more than one kilometre from the shore.

Shearman used his smart watch as a last hail Mary to send out an SOS alert and treaded water until he was found.

“I tried that emergency feature out of desperation and I was pretty astounded when I actually made the call through to triple zero,” Shearman told 9News.

Shearman treaded water for 20 minutes before his rescue.

“I stayed on the line until the chopper came over the horizon and scooped me up,” he said.

He reunited with the rescue team to film a safety campaign for Apple.

Westpac Rescue crew officer Alex Carroll recalled saving Shearman from the sea.

“He was obviously tired and exhausted and [we] just gave him a helping hand to the beach,” Caroll said.

Shearman’s story of survival is featured in Apple’s new campaign launched last week.

“[It] absolutely did save my life, invaluable,” said Shearman.

“I wouldn’t be here today without it.”

Several other smart watches on the market have other potentially life-saving features, including an ECG monitor on a Garmin device and stress-level monitoring on a Samsung Galaxy Watch.