Beachgoers may be safer thanks to a new technology that has the potential to update rip currents in real time.
A rip current is a narrow, fast-moving stretch of water away from the shore. They can reach speeds of 2.5 meters per second, faster than the fastest Olympic swimmers.
NIWA and Surf Life Saving New Zealand (SLSNZ) have developed a state-of-the-art rift identification tool using artificial intelligence (AI) and deep learning. In trials, the tool has shown about 90 percent accuracy in detecting riptide in videos and images. The work was published in the journal Remote Sensing.
NIWA coastal scientists Dr Christo Rautenbach and Neelesh Rampal said the technique had been tested on a large number of images from different coastal environments and they hoped it could eventually be used by beachgoers to alert them to rip currents.
“We hope that by using cameras and drones on the beach, the tool will be able to scan video footage and notify people of the presence of a rift. Depending on the beach and environmental conditions, it can be difficult for even a knowledgeable surf lifeguard to identify a rift. Other than that Also, some beaches are remote or very large, so surf lifesavers can use all the extra help they can get!” Dr Lautenbach said.
The technology was developed by feeding millions of coastal aerial images, along with artificial rain and fog data, into the AI model to teach it to identify where cracks occur in real time, regardless of weather conditions and camera angles.

The “warmer” color is where the AI focuses — it gives a probability score, with varying degrees of confidence, that a potentially deadly riptide exists in the area. [NIWA]
Adam Wooler, Special Projects Manager at SLSNZ, said that once operational, the technology would be invaluable for people to get out and enjoy our beautiful coastline.
“This is just the beginning of our joint research to create more effective, accurate and reliable safety tools for New Zealand beaches. Rip currents can sweep even the strongest swimmers out to sea – 90 people were killed in New Zealand last year Drowning, 25 of those people drown on the beach, so we hope this technology will help reduce that number significantly,” Wooler said.
Rip currents are reported to be the most dangerous safety hazard for beachgoers around the world. An Australian study published in 2013 showed they killed more people on Australian soil than bushfires, floods, cyclones and shark attacks combined.