CLASS 1: SIMPLE - Flat water with some riffles; like a swimming pool with current.
CLASS 2: MODERATE - Larger waves but no obstacles, Straight lines, easy splashing, and tame.
CLASS 3: DIFFICULT - Longer and rougher rapids. Maneuvering is necessary in heavy waves and around obstacles but paddling is easily mastered.
CLASS 4: VERY DIFFICULT - Steeper, longer drops, looming obstacles, technical turns, precision movements, occasional "swimmers".
CLASS 5: BORDERLINE - Rafting, transcended to the limits of control. Crews must be agile, aggressive, and follow commands instantly. Should be physically and mentally prepared for adventure and inherent risk. While not absolutely required, we strongly suggest that everyone has happily experienced class 4 rapids before tackling class 5. Make no mistake. . . this is big, tough and difficult water.
CLASS 6: UNRUNABLE - Or, at the very best, survived only with a choir band of angels perched in your lap! Hiding under the bed is safer!