Scientists at the University of Plymouth are teaming up with Cornwall's beach lifeguards to investigate potentially dangerous rip currents.
Video cameras and GPS devices will measure rip current speeds and directions under various tidal states.
The RNLI said they were a major problem for surfers, swimmers and bodyboarders, dragging them out of safe depths.
The six-week tests start in May with the aid of a £500,000 grant from the UK Natural Environment Research Council.
Researchers hope the tests, which will be repeated in September, result in a predictive model that can be used to forecast when and where the rip currents will occur.