WRIGHTSVILLE BEACH — Tropical Storm Ana has stirred up dangerous currents on North Carolina beaches-- currents better known as riptides. The riptides came from powerful waves in the storm.

As the water pounds the coast, it searches for a way out. Once the waves finally reach a channel, the water rushes out to sea, causing a riptide. The effect won't normally endanger an experienced swimmer, but it's reason enough for lifeguards to be concerned.

A calm day at the beach can hide many of the storms that brew in the ocean. As the tide goes out, the ocean can stir itself up and out causing riptides that can challenge even the best of swimmers.

Lifeguard Johnny Todd says riptides have been known to carry swimmers 150 yards out past the breakers. In that situation, an unexperienced swimmer may find him or herself in trouble.

A few years ago Todd Wakely was caught in a riptide. Luckily, he knew what to do. Instead of swimming back towards shore, he swam parallel to the shoreline. But not everyone can get out on their own. Last summer, Wrightsville Beach lifeguards had to save close to 200 people in one day-- all pulled out by riptides.

The lifeguards do what they can, but they know it can take only a matter of seconds for a riptide to pull a swimmer into dangerous water.

There have been no problems recently at Wrightsville Beach because of riptides, but Carolina Beach was forced to close because the tides were too strong for swimmers.

Lifeguards advise swimmers to take a good look at what the water is doing before going in.

Riptides are generally not dangerous, they will not pull you under. Most people get in trouble when they try swimming directly into the riptide. So it's best to swim parallel to shore to get out of the current. Also when swimming in an unfamiliar area, ask the lifeguard about any dangerous spots.

A good sign of riptide infested water is a foamy and choppy appearance. The water is also dirtier because the waves have turned up sand. Once you're out of an area where there are no waves, there's a good chance you're also out of the riptide.