|1||Easy||Waves small; passages clear; no serious obstacles.|
|2||Medium||Rapids of moderate difficulty with passages clear.|
|3||Difficult||Waves numerous, high, irregular; rocks; eddies; rapids with passages clear through narrow chutes requiring expertise in maneuvering.|
|4||Very Difficult||Long rapids; waves powerful, irregular; numerous rocks; boiling eddies; powerful and precise maneuvering required.|
|5||Extremely Difficult||Exceedingly difficult; long and violent rapids, following|
each other almost without interruption; riverbed extremely obstructed; big drops, violent current and very steep gradient.
|6||Unrunnable||Don’t even think about it!|