離岸流；裂流；激流

離岸流 - Wikipedia

日文：｢ 離岸流 ｣（りがんりゅう）.

中文：離岸流；裂流；激流

http://en.wikipedia.org/wiki/Rip_current

A rip current is a strong flow of water returning seaward from the shore. It is often mistakenly called a "rip tide" or "riptide", though the occurrence is not related to the tides. Colloquially a rip current is known simply as a rip. Although rip currents would exist even without the tides, tides can make an existing rip much more dangerous (especially low tide). Typical flow is at 0.5 meters per second (1-2 feet per second), and can be as fast as 2.5 meters per second (8 feet per second). Rip currents can move to different locations on a beach break, up to a few hundred feet a day. They can occur at any beach with breaking waves, including the world's oceans, seas, and large lakes such as the Great Lakes in Canada and the United States.