(CBS) — When people think of dangers in the ocean, sharks may be the first thing that comes to mind (especially given this summer’s spate of shark attacks off North Carolina). But it turns out that one of the most dangerous things in the water is a rip current.
According to the United States Lifesaving Association (USLA), more than 100 people nationwide die every year after getting caught in a rip current, and at least 80 percent of lifeguard rescues are due to rip currents.
“Rip currents are fairly common because sandbars are constantly shifting and changing based on the weather,” Tom Gill, a spokesperson for USLA, told CBS News. “The ocean is such a dynamic environment. So you’ve got to be able to swim, you’ve got to have some survival skills.”
What is a rip current?
A rip current is a powerful channel of water that can move at speeds of up to eight feet per second. As the rip current moves away from the shoreline, it can drag even the strongest of swimmers with it.
“The biggest misconception is that they actually pull people under, but they pull people out,” Gill said.
Although rip currents are not easy to spot, some common characteristics of rip currents include a channel of water that is choppy and that appears in a churning motion, a line of sea foam or seaweed that is moving rapidly away from the shore, or a break in a pattern of waves coming towards the shore.
And they don’t just happen in the ocean. According to USLA, “rip currents can occur at any surf beach with breaking waves, including the Great Lakes.”
What to do if you’re caught in a rip current
The first and most important thing to remember if you are caught in a rip current is not to panic.
“Lots of times people panic and try to fight the rip current and exhaust themselves and go underwater,” Gill said.
To get out of the rip current, he advises swimming sideways, parallel to the beach, until you get out of it and then continue to swim diagonally towards the shore. If you can’t get out of the rip current this way, float on your back or tread water until you can. You should also wave your arms and call out for help.
Practice safe swimming
You should always swim in an area with lifeguards.
Patrolled areas post surf hazard warning flags or rip current educational signs so swimmers know about surf conditions and rip current activity.
In addition, NOAA’s National Weather Service issues surf zone forecasts to help lifeguards and local officials determine if the water is safe for swimming.
The U.S. Swim Schools Association urges parents to review rip current safety measures with their children and introduce kids to the lifeguard in the area before they go into the water.
“It’s always good to check in with the lifeguard when you arrive at the beach,” Gill said. “If you see red flags flying, check in and see what the restrictions are.”
© 2015 CBS Interactive Inc. All Rights Reserved.