Easy; Waves small; passages clear; no serious obstacles. (Please see Rafting introduction for further clarification) ...

Medium: Rapids of moderate difficulty with passages clear. Requires experience plus suitable outfit and boat. (Please see Rafting introduction for further clarification) ...

Difficult: Waves numerous, high, irregular; rocks; eddies; rapids with passages clear though narrow, requiring expertise in manoeuvring; scouting usually needed. Requires good operator and boat. (Please see Rafting introduction for further clarification) ...

Very Difficult: Long rapids; waves high, irregular; dangerous rocks; boiling eddies; best passages difficult to scout; scouting mandatory first time; powerful and precise manoeuvring required. Demands expert boatman and excellent boat and good quality equipment. (Please see Rafting introduction for further clarification) ...

Extremely Difficult: Exceedingly difficult, long and violent rapids, following each other almost without interruption; riverbed extremely obstructed; big drops; violent current; very steep gradient; close study essential but often difficult. Requires best person, boat, and outfit suited to the situation. All possible precautions must be ... read more..

Unraftable: This grade of river is pushing towards or beyond the extremes of navigability. (Please see Rafting introduction for further clarification) ...