Technology trial proves power of rips

Friday, 16 December 2016

New technology to map rip currents at New Zealand beaches this summer has been successfully trialled at Mount Maunganui.

The project, funded by global Antivirus Software Company Emsisoft, uses 'drifters' to plot GPS data and drones to accurately map the rip currents and their behaviours to measure the physical layout of the (topographic) headland rip current across a range of different swell, tidal and wind conditions.

The methodology and logistics of the fieldwork were trialled at Mount Maunganui at the end of November by Surf Life Saving New Zealand with the assistance of volunteer lifeguards from Omanu, Mount Maunganui and Papamoa Surf Life Saving Clubs.

Surf Life Saving New Zealand national lifesaving manager Allan Mundy says the custom made drifters performed as expected, replicating a swimmer caught in a rip. The drift patterns showed both drifter exits and recirculation within the surf zone.

"The trial proved just how powerful rips are. What was interesting was the fact that even in little surf, the drifters travelled very fast in the surf. One of the drifters broke away from where it was predicted it would go and went half a kilometre down the beach in the opposite direction. This illustrates the transient power of rip currents and the danger the Mount Maunganui rips pose to the public," he says.

Mr Mundy says the information gathered proves that rips don't work exactly the way we thought.

"There's still a lot to learn but the early success of the project at Mount Maunganui can be used as a template for further trials at more locations across the country this summer," he says.

The information gathered through the project will be added to a database which will assist in future current predictions during lost person's searches and the method will be used to set a data standard for future research on additional sites around the country.

Click here to view photos from the trial.


For more information, please contact:

Lisa Smith, Media & Communications Manager, SLSNZ
Phone 0276 488 823