the.com/whitewater

means Fast, turbulent river water made frothy white by rushing over rocks and steep drops — and, by extension, the rafting sport done on it.

from A straightforward compound of 'white' and 'water,' first used descriptively in English for the foamy, aerated look river rapids get when water is churned violently over rocks — the air bubbles scatter light and turn the water white instead of clear. The term later extended to the recreational sport of navigating those rapids by raft or kayak, a usage that picked up steam in the 20th century as the activity became popular.