Rip currents aren’t just a threat to swimmers entering the water from the beach side. These narrow currents in the surf zone may extend out 100 yards or more from the shore (that’s the size of a football field). The size of a rip current can extend 50 to 100 feet lengthwise. So if you’re spending a leisurely boating afternoon on the hook, not too far offshore, those waves breaking against the beach may appear cool and inviting, but for safety’s sake, don’t jump in just yet!

It’s important to assess the waves for dangerous rip currents. According to the U.S. National Oceanic and Atmospheric Administration (NOAA), “Rip currents are powerful, narrow channels of fast-moving water that are prevalent along the East, Gulf, and West coasts of the U.S., as well as along the shores of the Great Lakes. Moving at speeds of up to eight feet per second, rip currents can move faster than an Olympic swimmer.”

If a world-class swimmer can’t compete against a rip current moving at around five miles per hour, getting caught in one may prove fatal to the average person taking a summer dip. The force and speed of the water sweeps you away from would-be rescuers; panic and exhaustion swiftly set in, lowering your ability to survive.

Swimmers finding themselves in a rip current are advised to stay calm and swim parallel to the shore until the current’s pull ceases. While doing so, wave and yell for help.

Boaters should pay attention to beach closings or warnings issued to swimmers. Using your eyes before deciding to go overboard is also important. Though clues may not always be visible, NOAA lists these signs of a possible rip current:

• Differences in water color, water motion, incoming wave shape, or breaking point compared to adjacent conditions.
• Channel of churning, choppy water.
• Line of foam, seaweed, or debris moving steadily seaward.
• Break in the incoming wave pattern.