What causes a rip current—and how can you spot one?

You might worry about sharks, stingrays, or jellyfish when you’re at the beach but there’s something more dangerous on shores around the world—rip currents.

Rips do not pull you under the waves, they drag you further out to sea. When people panic and exhaust themselves trying to struggle against the current, they can drown.

Over 80 percent of lifeguard rescues in the United States, and 60 percent of Royal National Lifeboat Institution lifeguard incidents in the United Kingdom, are related to rip currents, partly because they are so difficult to spot. In June, five tourists drowned in four days off one Florida beach after getting caught in a rip current.

To protect yourself, here’s some clues to look out for and what to do if you get into trouble.

What is a rip current?

Rip currents are strong channels of water flowing away from the beach that typically form at breaks in the sand bar. They are caused by waves approaching the coastline straight on with nowhere to go.

“The water isn’t escaping to the left or the right, it’s piling up,” says Simon Boxall, teaching fellow at the University of Southampton’s National Oceanography Centre. “It has to escape somewhere and it escapes through a rip current.”

(Would the world really face chaos if the Atlantic's currents slow down?)

Rip currents can occur in any body of water with waves, including the Great Lakes, but are common at “classic” beaches that slope gently out to sea. “The wave gets refracted—it gets bent around—and the shallower the slope is towards the beach, the more parallel the wave becomes,” he says—meaning there’s a greater chance of a rip current. 

Boomerang Beach in Australia, Panama City Beach in Florida, and Lamu Island in Kenyaare all known for their strong rip currents, but you shouldn’t get complacent as they can happen at any beach with waves.

How to spot a rip current

The telltale signs of rip currents can include paths of darker water between white water, a break in the waves, or a channel of foam or sandy water moving offshore.

“If you see a dark gap heading offshore through the surf that is persistent in time and space, that’s probably a rip current,” says Rob Brander of the UNSW Beach Safety Research Group in Sydney, Australia, who goes by “Dr. Rip.” 

(6 tips to make your next beach trip more sustainable.)

To look for them, scan the beach for a few minutes from the side or higher up, such as on a sand dune. “It’s always harder to spot rip currents from the shoreline,” says Brander. “Don’t just glance.”

Rip currents are notoriously difficult to see, even for experts, and can change in minutes. “I've been surfing for 30 years,” says Chris Cousens, water safety lead at the RNLI in Wales. “When I go to new locations, I can’t always immediately spot rip currents.”

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Avoiding rip currents

Because people tend to avoid swimming in rough seas, incidents often happen when the waves look gentle.

“Most of our deaths occur on a nice weekend,” says Erik Heden, warning coordination meteorologist at the U.S. National Oceanic and Atmospheric Administration (NOAA)’s National Weather Service. “It's sunny out, it's hot… It doesn't look threatening.”

To stay safe, planning is key. Check the rip current forecast for your location (here’s the forecast tool for the U.S.) and don’t go into the water if there’s a high risk. “Maybe that's a pool day,” says Heden.

(The surprising ways sharks keep the ocean healthy.)

At the beach, before you enter the water, look for safety flags and make sure you understand what they mean—they’re different depending on where you are in the world—and swim near a lifeguard.

“Never, ever, ever swim by a jetty or pier,” says Heden, because there are often rips nearby.

What to do if you are caught in a rip current

If you find yourself in a rip current, the first thing to do is to try to put your feet down. If you can touch the seafloor, stand up and wade back to shore. “Lots of people, when they feel that sensation of being pulled into deeper water by a rip current, they forget that sometimes they're just within their own depth,” says Cousens.

If you can’t stand up, don’t fight to swim directly back to shore. Rip currents can be “faster than an Olympic swimmer so you cannot outswim them,” says Heden.

Stay calm and call for help. “Panicking alters your breathing and physiology and can quickly lead to drowning,” says Brander.

Think of a rip current like a river, says Boxall. “You’d never swim along a river to get out, you’d swim to the side.” Swim parallel to the shore until you get out of the current then make your way back to the beach.

But be careful to note whether the rip is actually coming in at an angle, says Brander. In some instances, by swimming sideways “you may find yourself actually swimming against the current.” 

To save energy and avoid fatigue, float on your back, making sure your airway is clear. “Float to live,” says Cousens. “Avoid the panic, rest, recuperate on your back.”

Helping others

If you see someone in trouble, call a lifeguard immediately, throw them a flotation device, and direct them where to swim.

Do not go into the water yourself. “Your natural reaction is to try to help,” says Heden. “The problem is, usually you go in after them, and you become the victim and they're okay.” 

Being aware of the conditions and what to do if you’re in a rip is the best way to stay safe. A rip current is “nothing to be afraid of,” says Heden. “It's something to respect.”