National Weather Service
National Weather Service United States Department of Commerce

rip current navigation bar-top

Rip Current science Rip Currents: At the Beach Rip Currents: Before You Go to the Beach Rip Current Surf and Rip Forecasts Rip Current Safety Beach Warning Flags, Red Closed, High Hazard; Yellow, medium hazards; green, low hazard; purple, dangerous marine life

weather-ready nation link

Rip Current Navigation bar, hover for links Beach hazards such as dangerous waves, algae blooms, debris, lightning, sun burn and more Frequently Asked Questions rip current education Photos of rip currents Stories from Rip current survivors beach signs, brochures, flyers, photos, stickers, video and more Rip current science links, glossary,S partner agencies, local resources Kids games and activities; Teen multimedia and online class resources surf zone fatalities by gender, age, month, state and type

Rip Current Questions and Answers

  • What is a rip current? Do rip currents pull people underwater? Rip currents are currents of water flowing away from the shore at surf beaches. They typically extend from near the shoreline, through the surf zone and past the line of breaking waves. The surf zone is the area between the high tide level on the beach to the seaward side of breaking waves.
  • What is undertow? There is disagreement among coastal scientists on the existence of a nearshore process called undertow, and hence there is not an agreed on definition for this word. Undertow is a term often and incorrectly used for rip currents. The best explanation for what many people attribute to undertow is as follows: After a wave breaks and runs up the beach, most of the water flows seaward; this "backwash" of water can trip waders, move them seaward, and make them susceptible to immersion from the next incoming wave; however, there is no surf zone force that pulls people under the water.
  • What the difference between a like runout, rip tide and rip currents? These terms, though once commonly used in certain regions, are incorrect. The National Weather Service, Sea Grant, and the USLA are working together to use consistent terminology to provide a clear rip current safety message to the public.
  • What happens to people caught in a rip current? People get in trouble when they are moved so far offshore that they are unable to get back to the beach because of fear, panic, exhaustion, or lack of swimming skills.
  • Are all rip currents dangerous? Rip currents are present on many beaches every day of the year, but they are usually too slow to be dangerous to beachgoers. Certain wave, tide and beach shape conditions can increase rip currents to dangerous speeds.
  • How do rip currents form? Rip currents are formed when waves break near the shoreline, piling up water between the breaking waves and the beach. One of the ways that this water returns to sea is to form a rip current, a narrow jet of water moving swiftly away from shore, roughly perpendicular to the shoreline.
  • How big are rip currents? Rip currents can be as narrow as 10 or 20 feet in width though some may be up to 10 times wider. The length of the rip current also varies. Rip currents begin to slow down as they move offshore, beyond the breaking waves, but sometimes extend for hundreds of feet beyond the surf zone.
  • How fast are rip currents? Rip current speeds can vary. Sometimes they are too slow to be considered dangerous. However, under certain wave, tide and beach conditions the speeds can quickly become dangerous. Rip currents have been measured to exceed 5 mph, slower than you can run but faster than you or even an Olympic swimmer can swim. In some cases they have been measured as fast as 8 feet per second. This is faster than the speed at which an Olympic swimmer can swim a 50-meter sprint. Under most tide and sea conditions rip currents are relatively slow. However, under certain wave, tide, and beach profile conditions the speeds can quickly increase to become dangerous to anyone entering the surf. The strength and speed of a rip current will likely increase as wave height and wave period increase.
  • Where should I look for rip currents?

    Rip currents most typically form at low spots or breaks in sandbars, and also near structures such as groins, jetties and piers. Rip currents can occur at any beach with breaking waves, including the Great Lakes. Rip current can be difficult for the average beachgoer to identify. Look for differences in the water color, water motion, incoming wave shape or breaking point compared to adjacent conditions. Look for any of these clues:

    • Channel of churning, choppy water
    • Area having a notable difference in water color
    • Line of foam, seaweed, or debris moving steadily seaward
    • Break in the incoming wave pattern
    • One, all or none the clues may be visible.
  • What is the Surf Zone and Surf Zone Forecast?
    • The Surf Zone is the area between the high tide level on the beach to the seaward side of the breaking waves.
    • The Surf Zone Forecast provides lifesaving information on beach hazards. This forecast typically describes the following parameters and hazards: Sky condition, precipitation, visibility, air temperature, wind speed and direction, wave height, surf temperature, tide information, rip currents, lightning, severe thunderstorms, and the ultraviolet index.
    • Most coastal NWS Forecast Offices issue a Surf Zone Forecast from Memorial through Labor Day or longer to reflect the swim season.
    • The Surf Zone Forecast product is available through the NWS Family of Services, NOAA Weather Wire Service, the Emergency Manager's Weather Information Network. It is also available over NOAA WeatherRadio.
    • What is the Rip Current Outlook? The Rip Current Outlook is a forecast of expected rip current conditions. The colored flags posted on surf beaches are the purview of the local beach patrol, lifeguards, or local law enforcement officials. These colored flags refer to one of any number of surf zone hazards. The colored flags reflect actual, current surf zone hazards. The Rip Current Outlook portion of the Surf Zone Forecast provides standardized terminology for describing this hazard.
      • Low Risk means it is safe to swim near a lifeguard, however, life threatening rip currents still may occur near groins, jetties, reefs and piers. Know how to swim and heed the advice of the beach patrol/lifeguards.
      • Moderate Risk means life threatening rip currents are possible in the surf zone. Only experienced surf swimmers should enter the water.
      • High Risk means life threatening rip currents are likely in the surf zone. Rip Currents are life-threatening to anyone entering the surf, even olympic level swimmers.
  • Does the NWS issue Rip Current Advisories or Rip Current Warnings? The NWS does not issue Rip Current Advisories or Warnings. That action is the responsibility of the local beach patrol, local lifeguards, or local law enforcement officials.
  • Why have I seen days when there was a moderate rip current risk and the ocean looked almost flat? Long period swells sometimes result in minimal wave action where the ocean surface is hardly perturbed, yet there is a greater than normal transport of wave energy into the surf zone which may result in an elevated rip current risk.
  • Why don't you issue outlooks during the winter because strong rip currents certainly exist? Rip Current Outlooks are issued during the swimming season, defined by the local National Weather Service Office. In the mid/northern latitudes, the waters are simply too cold for most swimmers during the winter.
On the Beach
  • Is there a connection between the Rip Current Outlook and the colored flags I see on the beaches? The Rip Current Outlook is a forecast of expected rip current conditions. The colored flags posted on surf beaches are posted by local beach patrol, lifeguards, or local law enforcement officials. These colored flags refer to one of any number of surf zone hazards. The colored flags reflect actual, current surf zone hazards.
  • When I go out surfing in strong onshore wind events, you mention that there is a high rip current risk. Why can't I find these rip currents so they can help pull me through the choppy surf? Sometimes the amount of water crashing into the surf zone can overwhelm many of the seaward flowing currents in the near shore ocean circulation. Very strong rip currents can still occur in these conditions, but they might be more widely spaced along the coast and hence more difficult to locate.
  • How can people avoid rip current problems? Take the following steps:
    • Before you leave for the beach, check the latest National Weather Service surf forecast.
    • Learn to swim in surf and never swim alone. It's not the same as a pool or lake.
    • Swim near a lifeguard.
    • Look for posted signs and warning flags, which may indicate higher than usual hazards.
    • Check with lifeguards before swimming and follow lifeguard instructions.
    • Be cautious. Always assume rip currents are present even if you don't see them. If in doubt, don't go out!
  • How do lifeguards make a difference? Lifeguards are trained to: recognize rip currents, inform the public about rip currents, and rescue people caught in rip currents. The chance of drowning at a beach protected by lifeguards affiliated with USLA is 1 in 18 million.
  • What can people do if caught in a rip current? See our surviving the rip section.
  • How can people assist others who are caught in a rip current? You can help someone caught in a rip current by:
    • Alert the lifeguard. If no lifeguard is available, call 9-1-1.
    • Throw the rip current victim something that floats, a lifejacket, cooler, beach ball, float, etc.
    • Yell to the victim to swim parellel to the shore line until they excape the pull.
    • Many would be rescuers have drowned trying to help others. Don't become a victim while trying to help someone else! Call for help.
Safety and Preparedness
  • What role does the media play with this rip current education program? The media is an important partner in the dissemination of our Rip Current Outlooks. We're hoping more coastal television and radio stations will report the Rip Current Outlook in their weather broadcasts each day. The media will play a valuable role in increasing the public's rip current awareness, just as they have in NWS safety campaigns for other weather hazards, such as lightning.
  • What are the rip current outreach efforts underway by local NWS Forecast Offices? The Warning Coordination Meteorologist (WCM) at each office is a primary link between the WFO and the community. Many WCMs work with local lifeguards, Chambers of Commerce, local governments, and community groups to establish those partnerships critical to a successful rip current education program, which must include local scientists from Sea Grant universities, rip current outlooks from the NWS, and the protection and warnings provided by lifeguards to beachgoers.
  • How does Sea Grant outreach work? The national network of Sea Grant Colleges and institutional programs is committed to the transfer of research results to government agencies, to coastal communities and to the public. Over the past 25 years, many Sea Grant programs have worked hard to increase public awareness of rip currents through the use of beach and boardwalk signs, brochures, videos, seminars, and web sites. These outreach efforts are designed to help local residents and visitors familiarize themselves with rip currents, avoid these dangerous coastal hazards, and understand how to swim out of a rip current.
  • Where can people learn more about USLA and water safety?