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Scientists are making progress producing modelling systems which can predict rips on beaches up to a week in advance.
Coastal oceanographers Malcolm Green and Giovanni Coco, of the National Institute of Water and Atmospheric Research, have been studying video footage of the Tairua surf beach, in Coromandel, from which they are forecasting rip currents.
The information has already proven useful to the local surf lifesaving club which in summer was able to better assess and roster how many volunteer lifeguards were needed on a particular day.
Dr Green said the goal of the project was to better assess hazards from dangerous rips.
The Tairua site was chosen because it was one of the Niwa sites which operated webcams to record surf zone data which had been collected for more than five years.
Dr Green said they were getting "pretty good" at predicting where and when the rips would occur, with up to 75 per cent predicted. As waves got big, the rips got big, he said.
The wave heights and angle of their approach were used for wave modelling while the scientists also assessed the condition of the beach, using their knowledge of the beach morphology, or shape and structure, to improve their predictions.
Dr Green said the information could be used to help surf clubs to best use their resources.
Sean Ridler, chairman of the Tairua Surf Lifesaving Club, said the information provided by Niwa was already proving useful.
Over summer the rip forecasts provided a week ahead had helped the club organise its patrols.
Mr Ridler thought some of the variables could still be tweaked to improve what were already "reasonably accurate" forecasts.
Tairua could be a temperamental beach and at times was comparable to the more dangerous west coast surf beaches, he said.
Mr Ridler thought other surf clubs would find such information useful, although there were no plans at this stage to expand the project.
