SYDNEY (AFP) - A pair of Australian swimmers on Thursday (Jan 18) became the first people to be rescued in the ocean by a drone when the aerial life-saver dropped a safety device to distressed teens caught in rough seas.

Australia is leading the use of the technology in surf life-saving, with dozens of drones on trial on beaches around the country.

In what is believed to be a world-first drone surf rescue, two boys on Thursday got caught in 3m swells while swimming off Lennox Head in New South Wales, near the border with Queensland.

Beachgoers onshore raised the alarm to the lifeguards who then alerted the drone pilot, and the aerial life-saver was deployed in moments.

"I was able to launch it, fly it to the location, and drop the pod all in about one to two minutes," lifeguard supervisor Jai Sheridan told the Gold Coast Bulletin.

"On a normal day that would have taken our lifeguards a few minutes longer to reach the members of the public."

Other than being a little weary from their experience, the pair were reportedly unharmed.

Along with their ability to spot swimmers in trouble and deliver life-saving devices faster than traditional life-saving techniques, like launching surfboards or rubber dinghies, drones are being used in Australia to spot underwater predators like sharks and jellyfish.

Artificial intelligence is being developed using thousands of images captured by a drone camera to build an algorithm that can identify different ocean objects.

The software can differentiate between sea creatures, like sharks which it can recognise with more than 90 per cent accuracy, compared to about 16 per cent with the naked eye.

Some beaches in Australia have shark nets, but a government report last year called for their phasing out in favour of exploring a range of alternatives, including sonar technology and aerial patrols.

The inquiry found that nets did not guarantee public safety any more than other deterrents but caused significant damage to marine life.