- Class 1: Very small rough areas, might require slight maneuvering. (Skill level: Very basic)
- Class 2: Some rough water, maybe some rocks, might require some maneuvering. (Skill level: Basic paddling skill)
- Class 3: Small waves, maybe a small drop, but no very dangerous. May require significant maneuvering. (Skill level: Some experience in rafting)
- Class 4: Whitewater, medium waves, maybe rocks, maybe a considerable drop, sharp maneuvers may be needed.(Skill level: Exceptional rafting experience)
- Class 5: Whitewater, large waves, large volume, possibility of large rocks and hazards, possibility of a large drop, requires precise maneuvering. (Skill level: Full mastery of rafting)
- Class 6: Class 6 rapids are considered to be so dangerous that they are effectively unnavigable on a reliably safe basis. Rafters can expect a lot of whitewater, huge waves, huge rocks and hazards, and/or substantial drops that will have severe impacts beyond the structural capacities and impact ratings of almost all rafting equipment. Traversing a Class 6 rapid has a dramatically increased likelihood of ending in serious injury or death compared to lesser classes. (Skill level: Full mastery of rafting, and even then it may not be safe
