原来在一些看起来十分安全的沙滩边上，也隐藏着“沉默的杀手”！离岸流在任何天气条件下且多种类型的海滩上都可能发生，与巨大声响的海浪不同，离岸流不会引起人的注意，直到人身陷其中才会发觉离岸流长什么样，那么什么是离岸流？要如何识别？万一遇到如何自救呢？
If you see the water do this, get out fast.
If you don't, you might get caught in a riptide.
What are the warning signs?
And which direction should you swim if you wanna survive?
This is WHAT IF and here is what will happen if you were caught in a riptide.
Every year, beach lifeguards rescue tens of thousands of people.
Four out of five times, it's from these rip currents, also called riptides.
But you can avoid them.
Keep track of suspiciously calm areas between the waves, and watch for different colors in different spots.
This could indicate that a riptide is churning up sand, sediment and seaweed.
