A new iPhone alert feature turned out to be the saving grace of two hikers stranded in a river in the South Island yesterday.

The feature sent an SOS message to responding emergency crews via satellite of the hikers’ location as water levels rose to an unsafe crossing level.

Police responded to reports at lunchtime yesterday of two people who were unable to walk out of an area in Arthurs Pass, where they had gone tramping near the Sudden Valley Stream.

Water levels had risen the night before and made rivers challenging to cross.

Police responded to reports at lunchtime yesterday of two people who were unable to walk out of an area in Arthurs Pass. Photo / West Coast Air Trust

West Coast Air Rescue Trust sent a helicopter to search for the hikers, they used the iPhone 14 feature to aid their rescue efforts.

“It’s pretty new technology so Personal Locator Beacons are still recommended on your travels but if you have a new phone check out this feature,” a statement on the Trust’s social media said.

There were no reports of any injuries.

The helicopter ended up lifting the hikers to safety and they were due to make their own way home from the Hawdon Shelter.

In April, the same iPhone feature alerted emergency services to a crash in rural Canterbury when a truck collided with a tractor.

“The phones can tell if there’s been an impact and it came through as a notification,” said Simon Lyford, Fire and Emergency Shift Manager.

“It’s only on the Apple iPhones, people need to have it turned on but it will come through to police - a computer-generated voice will give a longitude and latitude of the crash and say it’s detected a crash.”

The feature was introduced with the iPhone 14.