Why Rip Currents are Dangerous
Rip currents are the leading surf hazard for all beach goers. They are particularly dangerous for weak or non-swimmers. Rip current speeds are typically 1-2 feet per second. However, speeds as high as 8 feet per second have been measured–this is faster than an Olympic swimmer can sprint! Thus, rip currents can sweep even the strongest swimmer out to sea.
More than 80% of water rescues on surf beaches are due to rip currents.
Rip currents can occur at any surf beach with breaking waves, including the Great Lakes.
What is a Rip Current?
A rip current is basically a strong, narrow current flowing from the shore out to sea (see figure above). Often, these currents can flow up to speeds of 2 knots (2.3 mph), and usually flow perpendicular to the shoreline. Most rip currents are no larger than 50 ft in width, but some can be up to several hundred feet wide. Rip currents are often referred to as “rip tides,” which is an incorrect term because rip currents can form at any time, regardless of the tidal conditions.
Rip currents are also often confused with an “undertow” which is actually the backwash of a wave flowing downhill with enough force to knock down a swimmer and pull them into breaking waves. A rip current, however, is something completely different and only carries a swimmer out away from the beach.
How Do Rip Currents Form?
A good way to visualize the origin of a rip current is to imagine that you are walking from the beach out into the water. Eventually, you may go down into a trough, or ditch, and then come up onto a sandbar. Rip currents are formed when fairly large waves are breaking on an offshore sandbar. The power of the breakers tends to trap water by forcing it down into the trough on the nearshore side of that sandbar. After enough water has been forced into the trough, it is able to force its way out against the breaking waves. This results in the formation of a river of water heading out to sea (see figure at left). This current begins to scour, or erode away, a channel through the sandbar, which strengthens the rip current. Feeder currents, which run parallel to the shoreline, feed more water into the rip current, thus increasing the strength of the current even more. Often, strong onshore winds contribute to the formation of rip currents by blowing more water near the shore and into the trough.
How Do You Escape a Rip Current?
The most important thing to do if you are caught in a rip current is to stay calm and not panic. It is also important that you don’t attempt to swim against the current, because rip currents are very strong and even the best swimmers cannot fight a rip current. If you attempt to swim against the rip current you will very quickly become exhausted. There are two ways to escape a rip current. The first is to swim parallel to the shore line, perpendicular to the rip current. By doing this you are essentially swimming out of the rip current, not against it. Once you are out of the rip current you can swim inshore, being careful not to be pulled back into the rip current by feeder currents. One way to avoid this is to swim at a diagonal back to the beach. Another option for escaping a rip current is to allow the rip current to carry you out past the sandbar. Once the rip current reaches the sand bar, the trough is no longer feeding water into it, and it dissipates. Once you are out of the rip current you can swim back inshore on either side of the rip current, again avoiding feeder currents which could sweep you back into the rip current. By surfing in areas watched by surfguards, you increase your chances of being seen and helped by someone on the beach.
Saving Someone Caught in a Rip Current
Typical victims of rip currents are young males, who are usually fairly strong swimmers. On days when rip currents are present, the water is usually rough enough that most people would not be in the water anyway. Many times, those who drown are trying to save somebody else who is already caught in a rip current. If you are attempting to help someone who is caught in a rip current it is imperative that you have a flotation device, such as a surfboard or raft. Since rip currents do not pull a swimmer under the water, you are safe as long as you are floating. Most drownings occur when swimmers panic and become exhausted trying to swim against the current.
How Do You Spot a Rip Current?
Rip currents do not form when the ocean is relatively calm with small waves. As a result, the first thing to look for are fairly large waves breaking offshore. Some violent rip currents are clearly visible, while smaller ones are more difficult to detect. The following elements are characteristic of rip currents: foam, bubbles, seaweed, straw, or other debris flowing out from the shore through the breakers, a place where the waves aren’t breaking regularly due to the current, or water discoloration from the sandy bottom being disturbed by the interactions between the rip current and the waves (see figure above). A good rule to follow is that if you see anything that looks unusual or different, simply avoid it and go swim somewhere else.