CLASS I:
Easy

Fast moving with riffles and small waves. Few obstructions, easily avoided. Low risk. Easy self-rescue.

CLASS II:
Novice

Straightforward rapids; wide, clear channels evident without scouting. Occasional maneuvering. Rocks and medium waves easily avoided by trained paddlers. Swimmers seldom injured.

CLASS III:
Intermediate

Rapids with moderate, irregular waves that can swamp open canoes. Strong eddies and currents. Complex maneuvers and good control required in tight passages and around ledges. Large waves or strainers easily avoided. Scouting advisable for inexperienced parties. Self-rescue usually easy; group assistance may be required. Injuries while swimming are rare.

CLASS IV:
Advanced

Powerful, turbulent and predictable rapids; large, unavoidable waves and holes or constricted passages. Fast, reliable eddy turns and precise boat handling needed to initiate maneuvers, scout rapids or rest. Rapids may require "must" moves above dangerous hazards. Strong Eskimo roll highly recommended. Scouting necessary first time. Self-rescue difficult; skilled group assistance often needed. Moderate to high risk of injury to swimmers.

CLASS V:
Expert

Extremely long, obstructed or violent rapids with exposure to added risk Possible large, unavoidable waves and holes or steep, congested chutes. Eddies may be small, turbulent, difficult to reach or non-existent. Reliable Eskimo roll, proper equipment, extensive experience, high level of fitness and practiced rescue skills essential for survival. Scouting recommended but may be difficult. Swims are dangerous. Difficult rescue for experts.

CLASS VI: Extreme & Exploratory

These runs have almost never been attempted and often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are very severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions.