Whitewater Classification Scale
River runners use a system to classify the difficulty of a river or a particular rapid. The classifications are as follows.
Moving Water with a few ripples and small waves. Few or no obstructions.
Easy rapids with waves up to 3 feet and wide, clear channels that are obvious without scouting. Some maneuvering is required.
Rapids with high, irregular waves, narrow passages that often require complex maneuvering. May require scouting from shore.
Long, difficult rapids with constricted passages that require precise maneuvering in very turbulent waters. Scouting from shore is necessary and conditions make rescue difficult.
Extremely difficult, long and violent rapids with highly congested routes, which should always be scouted from shore. Rescue conditions are difficult and there is significant hazard to life in the event of a mishap.
Difficulties of Class V carried to the extreme of navigability. Nearly impossible and very dangerous. For teams of experts only, after close study has been made and all precautions have been taken.