Everything You Ever Wanted to Know About Rip Currents

The sea is a tough place to swim, not only for novice swimmers, but also for experienced swimmers. Hundreds of deaths take place around the world as a result of drowning, apart from deaths due to man-overboard situations. While waves can be considered the culprit for these accidents, and large waves are certainly frightening, it’s not the waves themselves but something else known as the rip currents beneath them that are responsible for drowning hundreds of unprepared swimmers. So before you plunge into that calm looking sea, learn a little about the rip tides that lurk beneath and follow some basic safety measures while swimming in the ocean.

Rip currents are known as the most dangerous ocean phenomena which can sweep even the strongest and most experienced swimmers off their feet and out to sea. The article describes what a rip current is and how a rip current works.

A rip current is generated in sea water when a strong flow of water is trying to return seaward along the shore. When the wind pushes the waves to the shore, the previous wave near the shore is moved sideways before it tries to get back to the sea. This constrained water is accumulated along the shore line and generates a strong current that is continuously trying to push the constrained water back to the sea. This phenomenon results in the generation of currents known as rip currents.

Rip currents are so strong at the surface that they disrupt even the strongest incoming waves, making the water surface unusually calm. Beneath the surface, the currents are so strong that even the strongest experienced swimmers have to struggle to break free, whereas an inexperienced swimmer can easily panic and drown when caught in a rip current's grip. Have a look at the image below to have a better idea of rip current formation.

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One important factor that results in the drowning of a person is an undertow that is created as a result of rip currents. The rip currents always stay along the shore and are continuously trying to go back to the sea. If the incoming waves are not strong enough, these currents try to escape during this "weak wave" instances. However, if there are no weak waves, the rip currents escape from beneath the strong waves, resulting in an undertow that pulls the swimmer inside the water. Drowning by a riptide or rip current has been the result of several deaths around the world.

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Rip currents can pull anything and everything that gets in the way of its flow. These currents move in an extremely erratic pattern. A stream of rip currents is difficult to indentify as the surface of the water is deceptively calm. However, scientists have come up with a way to identify these currents.

An experiment carried out by the scientists included colour dyes put in a pool generating rip currents. The dye's course or movement was recorded. The movement of the dye depicted an extremely irregular pattern, which not only made it difficult for a swimmer to escape but also took him or her almost to the bottom of the pool. This makes it difficult for the swimmer to identify the flow and current and also makes it difficult to swim.

There are also computer systems that can measure and predict the physical processes taking place at and near the shore up to a depth of 10 meters. This system measures the direction of the wave movement and the flow of underwater sediments and currents, analysing and forecasting any unprecedented change in the movement of waves. The rip currents can stay at the same place for weeks and sometimes even for months. These methods can be used to predict rip currents weeks before they are generated.

How to tell if there is a rip current? You can basically take these signs for the possibility of rip currents:

1. Water is deceptively calm
2. Colour of water is different in that area
3. Objects are moving away from shore
4. Presence of foam

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There are few ways to identify and escape the rip currents. The colour of the rip current area will be different from the surrounding area. Also the waterline near the rip current is lower than the rest of the water line.

In case a person is caught in a rip current, the first thing he or she should do is not to panic. If the person is trying to swim against the currents, back to the shore, he will get easily tired which will make him drown. The best way is not to swim against the waves but to swim parallel to the shore and allow the waves to bring the swimmer back to the shore. Look at the diagram below for a clear picture.

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Science Daily site

Image Credits

http://weblogs.sun-sentinel.com/news/weather/hurricane/blog/ripcurrent.jpg

http://www.co.st-johns.fl.us/BCC/Fire_Rescue/images/rip_currents.jpg

http://www.erh.noaa.gov/er/akq/rip/Image2.gif

http://www.srh.weather.gov/data/www/html/srh/ripcurrents/images/ripcurrent2.jpg

New York Daily