Maneuvering required to avoid obstacles and through narrow channels. May require scouting from shore. Advanced Very Difficult. Steeper, longer, with numerous obstacles and constricted passages. Scouting from shore is often necessary.
Rescue is difficult.
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 mishap. Crazed Team of Experts Ultimate Difficulty.