SCALE OF RIVER DIFFICULTY

The difficulty of a river is classified on a scale of I to VI

1. Waves small; passages clear; no serious obstacles
2. Rapids of moderate difficulty with passages clear. Good for canoes
3. MEDIUM: Waves numerous, high, irregular; rocks; eddies; rapids with passages clear through narrow chutes requiring expertise in maneuvering rafts and kayaks
4. DIFFICULT: Long rapids; waves powerful, rocks; boiling eddies; powerful and precision required.
5. VERY DIFFICULT: Exceedingly difficult; long and violent rapids; following each other almost without interruption; riverbed extremely obstructed; big drops, violent current, and steep gradient.
6. UNRUNNABLE