white·wa·ter 
(wītwô′tər, -wŏt′ər, hwīt-)
(wītwô′tər, -wŏt′ər, hwīt-)n. also white water
Turbulent or frothy water, as in rapids or surf.
adj. also white-water
Of, relating to, intended for, or taking place on whitewater, especially in river rapids: whitewater rafting.