a part of a river that looks white because the water is moving very fast over rocks （河水湍急流过岩石时呈现的）碎浪水花，白色水域 
a stretch of white water 一段白色水域 white-water rafting 激流漂流运动
a part of the sea or ocean that looks white because it is very rough and the waves are high （海洋的）白色水域，惊涛骇浪的水域
