GRADE I - Flat water, no rapids, a splash or two with few or no obstacles
GRADE II - Bubbling current. Some maneuvering required but easy to navigate.
GRADE III - Exciting-thrilling rapids; with irregular waves/hazards
GRADE IV - Roller coaster rapids that require technical skill and careful maneuvering large irregular waves (difficult)
GRADE V - The hair-raising limit! Extended violent rapids with severe hazards.
GRADE VI - Nearly Unable to run. Extreme attention and caution required. Inadvisable some things to keep in mind when planning a river rafting trip in Nepal are that most of the white water is at an altitude of 650 - 1100 meters and there is a tremendous seasonal variation in water volume. During the rainy monsoon season, water levels rise to more than 10 times that of their low points. From mid-June to early September, the rivers are at full volume and operations are limited to the most adventurous rafting trips. Overnight programs are offered only on the Seti and Trisuli Rivers