Rip "Tides"

When waves approach the shoreline they induce a small shoreward flow of water known as "mass transport." The casual swimmer neither notices nor feels this weak flow. As the current reaches the shoreline, water builds up and seeks a path to return to the sea. The right conditions cause a narrow rip current which becomes quite strong.

John Fletemeyer, a professor at Florida International University named the three agents that make rips dangerous to people in the surf as wind waves, tides, and swells. When the wind is directly onshore, a speed of ten knots is sufficient to create some rip current danger. The danger intensifies with increased wind speeds. An oblique onshore direction also correlates to a rip current danger, but requires a higher wind speed. The danger from rip currents usually begins on the second day of a period of prolonged onshore flow, and does not end until twelve hours after the wind weakens or becomes offshore again. The greatest danger comes around the time of low tide and is related to the size of oceanic swells. Swells occur in the summer when tropical cyclones, moving in a northward direction, pass east of the area. They also appear in the winter when strong extratropical lows develop off the coasts of Georgia and the Carolinas. The larger the swells the greater the rip current danger.

Rips occur mostly during periods of large wave action and strong persistent on-shore winds. "Rip tide," "run-out," "washout," "seapuss," or "undertow" are popular terms referring to the rip current. A strong water-surface current of short duration flowing seaward from the shore defines a rip. Rips go in an easterly direction and may be difficult to see.

hole (neck)

6' water

Sand bar Sand bar

3' water 100-300' 3' water

long

Rip Current

15-20'

wide

/ Current 5-10 mph

Shore

As described by Ken Walters, the recreational director of the City of Lake Worth, Florida, the rip current occurs when two sand bars form perpendicular to the shore. A hole (washout), two to three feet deeper than the sand bars, occurs between them. This "neck" region is the channel of strongest current with speeds measured at faster speeds than the normal current on the sand bars. These speeds vary by the amount of water flowing into the trough. The current flows into the hole, hits the opposite bar, and shoots out through the hole at its "head." These sand bars and holes constantly change making sites unpredictable.

The primary distinguishing feature of a rip current is the direction of flow seaward through surf zone. Sometimes the rip runs obliquely from the shoreline, following the deeper marine life channels. The surface of a rip current contains either "white wash" bubbles from breaking waves or sediment and debris floating in water. After flowing beyond the breaking waves, the rip generally weakens, diffuses, and vanishes. Called the "head", this area is the telltale sign of a rip current.

head

neck

breaker

feeder Current

beach

According to a seminar by Fletemeyer rip current drownings happen mostly in the six hour period from two hours before to four hours after low tide. They take place when the wind is directly onshore most of the time or within thirty degrees of a normal course to the coastline. Most rips become dangerous after they have pounded the shore a while. Most drownings occur with winds of ten knots or greater. Those occurring under conditions with winds less than ten knots are victims under twenty years or over sixty years of age. Many occur when a person is pulled away from the sand bar into deeper water by the strong rip current in the neck region.

The lifeguard is the front line defense to rip current drownings. He is trained to see rips by noticing pockets of water heading out to sea rather than into shore. Signs he looks for are ripples going against the current or doing circular motions in the water such as eddys or whirlpools. Wave actions disguise this from the untrained eye. The lifeguard is a specially skilled person who must use his/her best judgement and exercise reasonable care for safety of all beach goers. Training, vigilance, judgement, and fitness become the calling cards for the lifeguard when it comes to the dangers of rip currents. He must know what a rip current is and how dangerous it can be and watch for any signs of rip currents. He must act immediately, using his judgement to react appropriately to protect swimmers and beach goers. The lifeguard must quickly empty the water of swimmers, station a lifeguard to prohibit beach goers from entering the water until the danger is over, and post signs closing the beach until it subsides. He must possess the swimming skill sufficient to rescue a swimmer in distress. He must have rescue training, including CPR, to properly care for any injured swimmer.

When caught in rip current, you become in danger of being carried offshore through the surf towards the ocean. That current can be too strong to swim against. By taking proper action you can escape a dangerous situation. Look for warning flags which may be posted along the beach. If caught in a rip current, do not fight. The current is usually too strong to swim against and you might exhaust yourself trying. If you're a poor swimmer and caught in the rip, wade sideways across the current until out of its pull. If a good swimmer, you can ride the current out beyond the sand bar where the pull will weaken. Then swim toward shore at an angle away from the rip current. Always swim with the regular current. Pick an object on the beach. If it moves away from you as you swim, it means you're making head way, but if it stays steady or goes ahead of you, you're in trouble. Turn on your back and float, letting the rip carry you out beyond its neck. The rip current itself will not pull you down but breaking waves could temporarily push you under water. Once beyond the surf, the rip current will weaken. Then swim up or down the coast, away from the rip current until well out of danger before swimming to the shore. Use the buddy system in the ocean for protection from pending danger and have children and the elderly wear fins for added power.

There is a need for a three-pronged attack in the fight to save lives from being swept away by rip currents - public education, proper lifeguard training, and a commitment to continue actively with the other two issues in order to reduce the level of danger that rip currents presently hold over the beach patrons. Seventy percent of beach goers are people over the age of fifty. Mr. Walters suggested that the Red Cross's education campaign should heavily include classes in water safety aimed at this population. The promotion of encouraging young people to pursue careers as lifeguards needs to be escalated and benefits to those seeking that vocation made more appealing. Swimmers are here to stay and so are the dangers of our oceans rip currents. Let us make sure our education to those dangers are current and we staff our beaches accordingly.