A rip current is a narrow, powerful current of water running perpendicular to the beach, out into the ocean. These currents may extend 200 to 2,500 feet (61 to 762 m) lengthwise, but they are typically less than 30 feet (9 m) wide. Rip currents can move at a pretty good speed, often 5 miles per hour (8 kph) or faster. Rip currents are often called "riptides," but this is inaccurate due to "tides" being the rising and falling of water levels in the ocean. They are also often mistaken for undertow, which is actually a current of water that pulls one down to the ocean bottom. Rip currents travel along the surface of the water, pulling one straight out into the ocean, but not underneath the water's surface. It is possible for one to get knocked off his or her feet in shallow water, however, an