Rip Currents occur near pier and jetties. They often are caused by storms. A rip current is a channel of choppy, churning water that can be powerful enough to drown a swimmer. You can tell a rip current by a difference in the color of the water or by a break in the wave pattern.
If you find yourself in a rip current, don't swim into the current and don't fight the current either. Instead, swim in the direction of the shoreline until you are out of danger. Call for help too.
If you are going to the beach, check the rip current forecast on the weather radio. Warning flags are posted to warn swimmers from going out to far on days that high rip currents are expected.