Whitewater difficulty scale WW I to VI
Also: WW scale, whitewater grades, Class I–VI
The whitewater difficulty scale ranges from WW I (easy) to WW VI (limit of navigability). It helps you assess a river section.
According to the German Canoe Federation and the ICF, as described on Wikibooks:
- WW I, easy: clear view, regular current and waves, small wave trains, simple obstacles.
- WW II, moderately difficult: clear passages, irregular current and waves, medium wave trains, weak holes, whirlpools and pressure water, smaller drops.
- WW III, difficult: clear-cut passages, high irregular waves, larger wave trains, holes, individual boulders and drops.
- WW IV, very difficult: passages not readily recognisable, scouting usually necessary, powerful holes, higher drops with recirculation.
- WW V, extremely difficult: scouting essential, extreme wave trains and holes, tight boulder gardens, high drops.
- WW VI, limit of navigability: generally impossible, possibly runnable at certain water levels, high risk.
A plus or minus refines the grade (for example WW II+). In the English-speaking world there's a similar scale with classes I to VI (International Scale of River Difficulty).
Warning: the grade applies to a particular water level. In high water a WW II river can become considerably harder and more dangerous.
Sources and further reading
Research as of 13 Nov 2026. We have marked manufacturer information as such.