CAROLINA BEACH, N.C. -- About 100 people in the U.S. drown each year because of rip currents, and around 80 percent of swimmers who have to be rescued in the ocean are caught in them.
Earlier this week, researchers launched GPS-equipped "drifters" into the Atlantic Ocean to get a better idea of how these deadly currents work.
A researcher says that any beach with breaking waves is going to have rip currents and if you don't know what a rip current is, you're at risk.
The scientists gather data from the GPS systems to identify the currents movement along the shores.
Rip currents claimed at least 83 lives last year, according to the National Weather Service. Experts believe the actual toll was even higher.