Rip currents: how they work and how to escape, with NWS and Japan Coast Guard advice

Rip currents are the hidden danger at surf beaches. The NOAA/National Weather Service (NWS) video on rip current safety says they account for 80% of beach rescues. This article goes beyond the short note in our water competency article, combining NWS science with the Japan Coast Guard's advice for beaches in Japan.

What a rip current is

• The NWS describes rip currents as strong, narrow, seaward flows of water that extend from close to the shoreline to outside the surf zone. Channel rip currents can reach up to 8 feet per second, on par with the fastest Olympic swimmers.
• The Japan Coast Guard says rips can reach 2 meters per second and are typically narrow, about 10 to 30 meters wide.
• Both point to structures: the NWS says rips are frequently found next to headlands, groins, jetties and piers, and the Japan Coast Guard advises not to swim near groynes and headlands.
• The NWS adds that rip currents often form on calm, sunny days, so a calm-looking sea is no guarantee.

If you are caught

The NWS video says to stay calm: a rip current won't pull you under, it pulls you away from shore. Fighting it straight in just wears you out. Its advice, matched by the Japan Coast Guard:

1. Relax and float to conserve energy.
2. If you are a good swimmer, swim parallel to shore until you are out of the current, then swim with the waves and let them push you to shore.
3. If you can't escape, float and wait for rescue (Japan Coast Guard).

Signaling, with a caution. The NWS says to wave and yell for lifeguards. The Japan Coast Guard's English Water Safety Guide says that if you can stand or float, raise one arm and wave it widely, but warns that if you have no flotation and can barely float, waving your arms vigorously may make you sink. Float first.

If someone else is caught

The NWS says to throw something that floats or extend a reaching object, and not to try a rescue yourself; one NWS office warns specifically against forming a human chain. In Japan, call 118 (Coast Guard), 110 or 119.

Before you swim (our suggestions)

• The NWS says to swim only at a beach with lifeguards; in Japan, choose beaches open for swimming.
• Stay away from jetties, groins and breakwaters.
• Put children in life jackets and keep them within arm's reach.

Note: "Break the Grip of the Rip!" is a registered trademark of NOAA. Our Japanese edition: 離岸流から身を守る.