Some sun this morning as Ana slowly moves toward land (copy)

Piers are among the place prone to rip currents. File/Staff

A rip current doesn't come out of nowhere. You're likely to see it form, usually as a break in the wave pattern or a spume of foaming water mushrooming beyond the breakers.

The problem is, you don't always see it.

A 15-year-old drowned in June off Fripp Island, believed to have been caught in a rip current or an undertow. At least four people died in rip currents off North Carolina during the same month, according to news reports.

A swimmer recently was pulled from a rip off Folly Beach.

Rip currents are undertows that develop when retreating waves form a swift channel through the bottom sand. Abrupt and powerful, they can pull a swimmer far from the shore.

Inlets, piers, jetties and groins are prone to them.

Across the state, and in the Charleston area particularly, rip currents haven't been much of a hazard so far this summer. Only a handful of rescues have had to be made at Charleston County Park and Recreation Commission-guarded beaches, said Nikki Bowie, the safety program manager.

But they are always a threat. More than 100 people drown in rip currents per year in the United States alone, according to the U.S. Lifesaving Association. In contrast, no one in the continental United States has died from a shark bite since 2012.

The conventional wisdom that swimmers should try to swim to the side — essentially parallel to the shore as the current pulls them out — might not be the best method, at least one researcher has controversially claimed. They should ride out the current: most times it curls back in, said oceanographer Jamie MacMahan, now at the Naval Postgraduate School.

The problem is, the currents don’t always curl back directly.

The commission’s beach lifeguards still are taught the protocol of the U.S. Lifesaving Association: work sideways out of the current until free, rather than fighting it. But they’re also told about the curling back-in phenomenon. It’s a situational judgment, depending on the strength of the rip, the swimmer and the person being rescued.

One good protocol before entering the water is to check the weather report and pay attention to warning signs on the beaches. When possible, swim at lifeguard-protected beaches.

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