Class IV Advanced, Very Difficult Steeper, longer with numerous obstacles and constricted passages. Scouting from shore is often necessary. Rescue is difficult. Class V Expert, Extremely Difficult Consists of large vertical drops, strong hydraulics, and very swift, irregular currents in heavily obstructed channels. Very violent rapids which must be scouted from shore.
Rescue is difficult with significant threat to life in the event of a mishap.
Class VI Crazed Team of Experts Class V whitewater carried to the outer limits of navigability. Nearly impossible and very dangerous. Rescue is extremely difficult with extreme threat to life in the event of a mishap. In any outdoor experience there are inherent risks that cannot be eliminated. A river trip in particular has inherent dangers that could cause injury including, but not limited to, death by drowning.