Learn Rip Current Safety: USLA has found that some 80% of rescues by USLA affiliated lifeguards at ocean beaches are caused by rip currents. These currents are formed by surf and gravity, because once surf pushes water up the slope of the beach, gravity pulls it back. This can create concentrated rivers of water moving offshore. Some people mistakenly call this an undertow, but there is no undercurrent, just an offshore current. If you are caught in a rip current, don’t fight it by trying to swim directly to shore. Instead, swim parallel to shore until you feel the current relax, then swim to shore. Most rip currents are narrow and a short swim parallel to shore will bring you to safety.