什么是离岸流？
We all love going to the beach in summer: the sun, the sand and the surf. But having fun doesn't mean we can forget about safety.
Rip currents are strong, narrow channels of fast-moving water that flow away from the shore. They are common on beaches around the world. In the United States, for example, they are found along the Atlantic and Pacific coasts and along the shores of the Great Lakes.
Rip currents can move at up to eight feet (about 2.4 meters) per second, which is faster than an Olympic swimmer. Swimmers who panic often try to fight a rip current by swimming straight back to shore. This puts them at risk of drowning, because they soon become exhausted.
Every year, lifeguards in the US rescue tens of thousands of people from rip currents, but it is estimated that around 100 people still die. If you are caught in a rip current, don't fight it! Swim parallel to the shore until you are out of the current, and then swim back to land at an angle.
The two terms are often mixed up, but rip currents are not the same as rip tides. A rip tide is a particular kind of current caused by tidal water rushing through narrow openings, such as the mouths of harbors, bays and estuaries.
我们都喜欢在夏天去海边：阳光、沙滩，还有海浪。可是玩得开心，并不代表可以忘了安全。
离岸流是一股股又窄又急、从岸边流向大海的强劲水流。世界各地的海滩上都很常见。以美国为例，大西洋和太平洋沿岸，以及五大湖的湖岸都有离岸流。
离岸流的速度可以达到每秒八英尺（约 2.4 米），比奥运会游泳选手还快。惊慌失措的游泳者常常想逆着离岸流直接游回岸边，结果很快就筋疲力尽，有溺水的危险。
在美国，救生员每年要从离岸流中救起成千上万的人，但据估计，每年仍有约 100 人因此丧生。如果你被离岸流卷走，千万不要跟它硬拼！先平行于海岸游，等离开了离岸流，再斜着游回岸边。
这两个词常常被混淆，但离岸流（rip current）和“rip tide”并不是一回事。“rip tide”是一种特殊的水流，是潮水从港口、海湾、河口这类狭窄的出口急速冲过时形成的。