Whitewater is the foamy, churning water that forms when a river flows rapidly over and around rocks, creating turbulence and air bubbles that make the water appear white. The faster the river moves and the more obstacles it hits, the more dramatic the whitewater becomes.

The term is most commonly used in whitewater rafting or whitewater kayaking, where paddlers navigate through these turbulent sections of river. Rivers with whitewater are rated from Class I (easy, gentle ripples) to Class VI (nearly impossible and extremely dangerous). A Class II or III river offers exciting rapids that can be good for beginners and families, while Class IV and V challenge even expert paddlers with powerful waves, steep drops, and complex routes through the rocks.

Whitewater forms because fast-moving water hitting rocks creates chaos: the water splashes up, swirls around, and traps thousands of tiny air bubbles. These bubbles reflect light, making the water look white or pale green instead of the river's normal color. When the river calms and deepens again, the bubbles escape and the water returns to its usual appearance.

Riding through whitewater requires skill, teamwork, and respect for the river's power. One wrong move can flip a raft or kayak, which is why paddlers wear helmets and life jackets and learn proper techniques before tackling serious rapids.