NOAA Magazine | NOAA Home Page NOAA's RIP CURRENT PROGRAM: FORECASTING AND RAISING PUBLIC AWARENESS ABOUT THE DROWNING MACHINE August 13, 2002 — Rip currents, often referred to as "drowning machines," are the most common natural hazard swimmers can encounter in the surf. They are common beach features that only become life threatening under certain combinations of beach shape, tide, wind and wave conditions. Although some beaches are more prone to rip currents than others, rip currents have been documented in almost every coastal location around the globe, including the Great Lakes. Rip currents are not just a coastal phenomena, they can also occur in large inland lakes and are a safety issue in the Great Lakes. These currents are commonly found near jetties, groins, piers, breaks in sand bars, and inlets. Rip currents are efficient, indiscriminate killers and are a threat to anyone who enters the surf. NOAA's National Weather Service estimates that approximately 100 people fall victim to rip currents along U.S. waters each year, and cause several hundred more deaths globally each year. Statistics reveal that rip currents account for nearly 80 percent of all surf related rescues each year (i.e., 22,000 per year in the United States alone); rank third among average yearly hazard fatalities—(heat (219), flooding (127), and rip currents (100); and cause more average deaths per year than lightning (71), tornadoes (65), hurricanes (16), winter (52) and cold (27). Fortunately, NOAA's Rip Current Program assists in both forecasting and raising public awareness about these "drowning" machines. What is a Rip Current? A rip current is a relatively small-scale, surf-zone current that flows away from the beach. They form as waves disperse along the beach causing water to become trapped between the beach and a sand bar or other underwater structure. The trapped water is acted upon by gravity and begins to return seaward. As the water flows away from the beach, it will seek a path of least resistance, such as a break in a sand bar. In general, rip currents are comprised of three components: Feeder(s), Neck, and Head. Feeder(s): The feeder portion is the fuel source of the rip current and the location where wave energy becomes focused. Points along the beach, for example, make excellent feeders as waves roll off one or both sides of the point. The classic rip current has two feeders, although one feeder can also sustain a rip current. Neck: The neck is the portion of the rip current where water flows away from the beach. The current speeds are greatest, thus making it the most dangerous part of a rip current. People caught in this region frequently try to swim directly against this current toward shore, but even an Olympic-class swimmer cannot make headway swimming against this current, which frequently reaches speeds of 5 mph. The neck may extend several hundred feet offshore and have a width which ranges from 30 to 100 feet. Head: The final segment of a rip current (i.e., where the neck ends) is called the head. In this region, the rip current begins to spread outward and its net seaward motion diminishes considerably—as you move farther from the shore—since the rip channel that supports the neck is limited seaward. People who find themselves in this area of the rip current find they have a long way to swim back to shore. What Makes Rip Currents so Hazardous? Education and communication are the keys to rip current safety. Many people, especially tourists, who visit a surf beach for a vacation are unaware of the danger rip currents pose. Swimming in a lake or pool is quite a different experience than swimming where waves and currents can move you around like a toy. When at the beach, the best source of information is the local beach patrol, who know all of the local nuances of beach safety, including the location and strength of rip currents. Make sure you ask them about conditions before going into the surf. At unguarded beaches, look for signs or flags to learn about any dangers and heed any advice given by these sources. Rip currents are often hard to identify, especially when the surf is roughened by wind-driven waves. There are, however, visual clues that are helpful in determining where a rip current is located. Unfortunately, most people overlook the warning signs or do not recognize them. Furthermore, many people assume that fair weather equals favorable surf conditions. Ironically, however, some of the worst rip current events have occurred on the most sunny and pleasant of days. Under these conditions, rip currents typically originate from a large storm swell, located several hundred miles off the coast. How to Escape Rip Currents Often people who encounter rip currents have little knowledge or experience dealing with them. They do not know how to respond and subsequently panic as they are carried farther away from the beach. In fact, people often die in rip currents when they try to swim directly toward shore against the current, tire and eventually drown. The situation often becomes worse when parents try to rescue their children caught in a rip current, because their first reaction is to rush into the water to save them. However, in the process, the parent can also gets caught in the rip current, thus endangering both their lives. To better protect themselves and their families, people need to understand what a rip current is and the safety guidelines that should be followed if a rip current is encountered. Specifically, if you become caught in a rip current, do NOT panic or attempt to swim against the current. Instead, swim parallel to the beach until you are out of the rip current. If it is too difficult to escape, then calmly remain afloat until the rip current dissipates (i.e., at the "head" of the rip current), which is typically just beyond the breaking waves. Once you are out of the rip current, swim diagonally back to shore. NWS Rip Current Forecasting Efforts NWS forecasters, in cooperation with Sea Grant Extension agents, life-saving officials, emergency management personnel and law enforcement staff, issue forecasts and statements to alert the public about the potential for strong rip currents. Rip currents can occur any day and at any location along our nation's beaches, but they can become extremely dangerous under certain conditions. Therefore, the most important objective in rip current forecasting is to identify those days where rip currents are the strongest and therefore the greatest threat to anyone who enters the surf. Over a decade ago, forecasters at the Weather Forecast Office (Miami, Fla.) identified a correlation between increased rip current related rescues/fatalities and certain oceanic and atmospheric conditions. Additional rip current research, compiled by WFO (Melbourne, Fla.), further supported these findings. Specifically, strong onshore winds and a large swell are two of the main "signals" that NWS forecasters look for in wind and detailed wave measurements. NWS forecasters also utilize the latest in wave modeling — the NOAA WaveWatch III model — to aid them in determining when large swells may approach from distant tropical cyclones or other large oceanic storms. NWS forecasters also rely on the network of weather data buoys along our nation's coastal and offshore waters—maintained by the National Data Buoy Center). The data from these buoys helps to break down the wave spectrum, allowing forecasters to identify swell and wave direction that may be critical for the formation of rip currents. Lastly, forecasters depend on information from the local beach services and lifeguards, who play a critical role in the success of the program by providing local knowledge and statistics for verification purposes. Based on this weather buoy data and wave modeling, NOAA forecasters are able to determine the daily threat of rip currents based on the Lushine Rip Current Scale, which classifies rip current danger on a scale from zero to five where zero indicates little danger and where five is the greatest danger. Once the daily threat is determined, a forecast and/or statement is disseminated to the public through the NOAA Weather Wire Service and broadcast via NOAA Weather Radio. Likewise, some NWS offices—such as Wilmington, N.C., and Melbourne, Fla.—post threat information in a graphical format on the Internet. NOAA Rip Current Outreach Efforts Rip current awareness is another significant part of NWS's Rip Current Program. This involves teaching safety guidelines and educating the public about the dangers associated with rip currents and rip current threat forecasting. Emergency managers are encouraged to include rip currents in their emergency planning. This includes routine risk assessment of those areas where rip currents readily form, training emergency responders and determining the type of response required for large rip current events. NWS offices have worked closely with Sea Grant in securing 500 rip current safety signs for installation along many of the nation's public beach access paths, parking lots, lifeguard stands and other sites. These signs — developed by North Carolina Sea Grant — educate the public about what a rip current is, identifies telltale signs of a rip current, describes what to do if you are caught in a rip current and lists relevant contact information, such as NOAA's new national rip current Web site. These signs provide information about the latest rip current research, important safety information, and other related resources. Florida's Sea Grant program is even considering publishing rip current information in Spanish—and other foreign languages—to accommodate the non-English speaking public. The North Carolina Sea Grant also offers rip current brochure, poster, and video to further enhance rip current awareness. NOAA's NATIONAL WEATHER SERVICE OFFERS RIP CURRENT SURVIVAL TIPS As millions of Americans flock to the beach this summer, NOAA's National Weather Service offers important tips to survive rips currents and surf conditions. Bathers can stay safe this summer by keeping in mind some simple rules: Do not overestimate your swimming abilities. If the surf is up, and you are not experienced with large waves, stay out of the water. If you are not an experienced swimmer and cannot keep yourself afloat for extended periods, do not enter the water when the surf is running. Learn to recognize dangerous ocean conditions and rip currents. As waves pile up onto the beach, the water forms rip currents as it heads back out to sea. You can usually identify these currents as rivers of white water flowing away from the beach. These currents are powerful and will pull even the strongest swimmers out to sea. Stay calm, do not panic. Your chances of surviving a rip current or any swimming experience are drastically improved by staying calm and maintaining your ability to assess the situation. Never fight the rip. If you find yourself being pulled out to sea, do not fight the current by trying to swim back to shore. Stay calm and go with the flow. Keep yourself afloat by treading water or swimming parallel to the beach. In a few minutes, the current will dissipate. Duck under the waves. Breaking waves pack a pretty good punch when they hit a floating object. The secret is to duck under the waves. By submerging yourself only 2-3 feet under the water, you will avoid almost all of a wave's impact and safely pop back up on the other side. You will only have to hold your breath a few seconds, and this simple maneuver—routinely used by surfers and experienced swimmers—can save your life. The other side of the "Impact Zone." Waves on any given beach usually break in an area known as the "Impact Zone." This is not a friendly place for swimmers or someone caught in a rip current. Just on the other side of the zone, however, conditions are generally calm, the rip current fades, and a swimmer can easily float over the waves while keeping their head above water. Catch your breath/call for help. After you have gone with the flow and have allowed the rip current to take you out past the "Impact Zone," you can catch your breath and signal for help. It may seem like you are very far from the beach, but you are generally safe here as long as you can tread water and keep yourself afloat. At this point, you can swim parallel to the beach to a calmer area to wait for help to arrive. Let the waves do the work. If no help is available and you need to get back to the beach on your own, swim with the waves back toward the beach. Take your time and remember to duck under the larger waves. Again, go with the flow, and soon, the waves will push you back toward the beach. Relevant Web Sites NOAA/NWS Rip Current Page Sea Grant North Carolina Sea Grant WFO Wilmington North Carolina Rip Currents WFO Wakefield Virginia Rip Currents WFO Melbourne Rip Currents WFO Miami Rip Currents National Data Buoy Center NOAA WaveWatch Model NOAA Weather Radio NOAA Weather Wire Service Media Contacts: Susan Weaver, NOAA's National Weather Service, (301) 713-0622 or Benjamin Sherman, Sea Grant, (202) 662-7095