New tech spots rips - the greatest danger to beachgoers in Aotearoa

Tuesday, 27 December 2022

The artificial intelligence developed by Niwa and Surf Life Saving New Zealand identifies potential rip currents with warm colours.

New technology developed by Kiwi scientists and surf lifesavers can help identify the greatest danger at New Zealand beaches this summer – rip currents.

Rip currents are narrow segments of water which travel away from the shore at speeds of up to 2.5m per second, which is faster than the quickest Olympic swimmer.

They are dangerous, but many people don’t know how to spot them – a study released last summer showed 78% of those surveyed were unable to identify a rip.

Niwa and Surf Life Saving New Zealand have developed a state-of-the-art rip current identification tool, using artificial intelligence and deep learning to spot the rips.

* Shark numbers are growing, but waves still a greater danger to swimmers this summer

* Study at Auckland's Muriwai Beach shows 78pc of people unable to spot deadly rip

Niwa's new technology could help identify deadly rip currents at beaches such as Coromandel’s Hot Water Beach.

The tool had 89% accuracy of detecting rip currents in videos and images in trials, according to a study published in the journal Remote Sensing.

The tool could be invaluable for people enjoying New Zealand’s beautiful coastline once it is put into use, said Adam Wooler, Surf Life Saving’s special projects manager.

Stay away from rocks and rips at the beach over summer, surf lifesavers say. (Video first published in November 2019.)

“This is only the beginning of our research together and our goal is to build even more effective, accurate and reliable safety tools for New Zealand beaches,” he said.

“Rip currents can sweep even the strongest swimmers out to sea – we had 90 people sadly drown in New Zealand last year, 25 of them on beaches, so we’re hoping that this technology helps to significantly reduce that number.”

Niwa coastal scientist Dr Christo Rautenbach said the technology has been tested on a large variety of images from different coastal settings.

“We hope that by using cameras and drones at beaches, the tool will be able to scan video footage and notify people of the presence of rip currents,” he said.

“Even knowledgeable surf lifeguards can struggle identifying rips, depending on the beach and environmental conditions. As well as this, some beaches are remote or really large, so surf lifeguards can use all the extra help they can get.

The technology was developed by feeding millions of coastal aerial images into the AI model, along with artificial rain and fog data, to teach it to identify where rips occur in real-time – regardless of weather conditions and camera angle.

Rip currents are reported as the most hazardous safety risk to beachgoers around the world.

An Australian study published in 2013 revealed rip currents have killed more people on Australian territory than bushfires, floods, cyclones and shark attacks combined.