Now that it’s beach season, there’s a serious safety concern. I’m referring to rip currents, which are not to be confused with rip tides.

These currents kill up to 100 people— and force tens of thousands of people to be rescued—each year in the U.S.

These channels of water are on every coast and around the Great Lakes, and can move as fast as eight feet a second.

A rip current can pull you out to sea, and they’re so powerful that you can become fatigued enough to drown.

The key for fighting rip currents is to swim parallel to the shore until it breaks, and then swim back to land at an angle.

Learn how to spot these currents from the shore: The National Oceanic and Atmospheric Administration has a visual guide to help you look for the darker bands of water that signify a rip current.

But they can appear deceivingly calm, so always pay attention to local beach reports and only swim where a lifeguard is on duty.

For more travel safety tips, check out:

• What You Need to Know About Traveling During Hurricane Season
• What Are the Safest Airlines in the World?
• How You Can Prepare for a Tsunami
• What You Should Know About Safety in National Parks

Keep reading for more travel tips.