Whats a Class I, II, III, IV, V, VI?
Class I : EASY - Waves are small; passages clear. No serious obstacles.
Class II : MEDIUM - Rapids of moderate difficulty with passages clear.
Class III : DIFFICULT - Waves are numerous, high, irregular; rocks; eddies; rapids with passages clear though narrow, requiring expertise in maneuvering.
Class IV : VERY DIFFICULT - Long rapids; waves powerful and irregular; dangerous rocks, boiling eddies; powerful and precise maneuvering required.
Class V : EXTREMELY DIFFICULT - Long and violent rapids following each other almost without interruption; riverbed extremely obstructed; big drops; violent current; very steep gradient
Class VI : DANGEROUS The difficulties of Class V carried to the extreme. Nearly impossible and very dangerous. For teams of experts only. Involves risk of life. Class VI rapids are not commercially raftable.
Note: The difficulty of a river may vary significantly with fluctuations in water level. The ratings listed usually refer to the rivers' difficulties at normal, summer levels. Don't judge a river by it's put-in pool and take-out, know what's downstream.