Five Types of Rip Currents

Don't get ripped!

 

Researcher:

Stephen P. Leatherman
Professor and Co-Director
Laboratory for Coastal Research

Florida International Univ.
Leatherm@fiu.edu

305-348-8364

Relevant Info:

YouTube: Dr. Beach on Rips

Break the Grip of the Rip

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Bar-gap rips on Outer Cape Cod, Mass.                    Credit: Stephen Leatherman

October 26, 2012

Contact: Christina S. Johnson, csjohnson@ucsd.edu, 858-822-5334

LA JOLLA – As part of a national public awareness campaign, one of America's foremost beach experts has recently described the five major types of rip currents in terms that can be understood by non-scientists.

Three of these types of rip currents – bar gap, structurally controlled and mega rips -– are common in California.

Mega rips are especially relevant now, as the soft swells of summer are replaced by bigger waves from the north Pacific.

Bigger waves mean stronger rip currents, as well as stronger longshore currents and narrower, steeper beaches. But, it is the "rips" that pose the greatest danger to public safety because they can so easily carry swimmers to deeper water, triggering panic – the worst possible response.

According to a recent journal article, rip currents are responsible for more than 100 deaths annually in the United States and for fully 80 percent of lifeguard rescues.

View NOAA Sea Grant's "Break the Grip of the Rip" campaign for more on swimmer safety.

"When people go to the beach, they should scan the beach, the water and the waves for a few minutes," says Stephen Leatherman, aka Dr. Beach, author of "Rip currents: types and identification" published in Shore & Beach, the journal of the American Shore & Beach Preservation Association.

Knowledge of these five types of rips is a way to build ocean smarts and awareness, both of which can help keep the beach fun, and safe, all year round. There should be no such thing as a bad day at the beach.

1) Bar-gap ripsPhoto: David Elder

(Above) An entire family stands at a beach in North Carolina in front of what looks like a patch of calm water great for swimming. In actuality, it's the path of a rip current, created by a gap in an offshore sand bar. Bar-gap rips are the most common type of rip current and thus the most dangerous to the public, but they are also easy to spot in advance. Look for calm, darker water between areas where the waves are breaking. Polarized sun-glasses can help you spot the dark patches.

2) Structurally controlled rips

Photo: Stephen Leatherman

(Above) Shell Beach in La Jolla, California at a very low tide on a surf-less day. The long, submerged rocks set up a well-known rip, known as the Shell Beach Express. Structurally controlled rips are created by permanent features along the coast, including submerged rocks, groins (jetties) or piers. The locations of these rips are somewhat predictable, particularly for certain swell directions, and hence relatively easy to avoid. Surfers often use these rips as a "free ride" to the surf. For novice beach goers, they are hazardous.

3) Mega rips

Photo: Huntington Beach Lifeguards

(Above) Huntington Beach in Orange County, California during a good swell. The swirl of white water past the surf is the tail end of the mega rip. The Huntington Beach Pier is about 1,800-feet in length.

Mega rips are formed by big waves, interacting with underwater formations, such as canyons or reefs, that focus rebounding wave energy. In general, the bigger the waves, the stronger the currents. Why? Bigger waves pump more water onto the beach and all the extra water must be drained away in either longshore or rip currents.

If the surf is up, it's best to avoid swimming unless you have ocean experience. Even good pool swimmers can get freaked by nature's unrelenting playfulness.

4) Flash rips

Photo: Delaware Sea Grant

(Above) Flash rips, marked by the red arrows, at a beach in Delaware. How can you tell these are rips? Look how the white water extends beyond the breaker zone and is climbing up the faces of the incoming waves. The foam is being carried in the rip. Watching the white water is good way to mentally tag what is going on in the surf zone. You can also look carefully at the texture of the water's surface to help you follow the direction of water movement.

Flash rips are mostly an East Coast phenomenon. On days when flash rips are possible, you will feel the wind on your face; the surf will be junky and blown-out, and there will be white caps farther out. Flash rips are very temporary and variable and weaker than rips created by true ocean swells. They can still be dangerous because of their unpredictability.

5) Cusped-shore rips

Photo: Chris Houser

Not a phenomenon found in California. These rips form on super flat beaches with sugary sand and offshore shoals – mounds of sand as opposed to long linear sand bars. The shoals steer nearshore currents, creating bow-shaped, scalloped or meandering shorelines. Pictured above is a beach on the Florida Panhandle with these characteristics. Note the sand cusps. Rips will form in the calmer water – the embayments – between the cusps. These rips are not nearly as strong as those powered by large surf but can nonetheless catch swimmers off guard. It's safer for children to swim and play in the small waves than in the embayments between the cusps.