What difficulty levels exist in river rafting?

Not every river flows the same. To classify, a scale from WW I to WW VI exists. “WW” stands for whitewater. Scale indicates current strength, wave size, need for experience.

Overview:
WW I (very easy): calm water, no obstacles. Like floating on a raft. Ideal for beginners.
WW II–III (moderate to intermediate): more speed, small to medium waves, occasional drops. Active paddling required, manageable. Perfect for athletic beginners and intermediates.
WW IV–V (difficult to very difficult): fast current, large waves, complex sections. Requires experience, reaction, clean technique. WW V is upper limit for commercial tours.
WW VI (extreme): serious. Huge waves, barely controllable, unsafe. Not part of guided tours. Only for expeditions with professionals.

Which level is right for you?
Guided rafting tours usually WW II to IV. Sporty to challenging, well supervised. No prior experience needed. Must enjoy activity and water. Guide knows the river. No need to choose the line yourself.