Currents

Tidal currents are horizontal water motions associated with the sea's changing tides. Thus, in the ocean, wave tides cause continuous currents that change direction 360 degrees every tidal cycle, which typically lasts six to 12 hours. These tides can be very strong—reaching speeds of 6 in (15 cm) per second and moving sediment long distances—or they can be weak and slow. Of interest to swimmers, rip currents are outward-flowing tidal currents, moving in narrow paths out to sea. The flow is swift in order to balance the consistent flow of water toward the beach brought by waves. In general, tidal currents are of minimal effect beyond the continental shelf.