Most tours whitewater rafting using the International Scale of River Difficulty to describe river conditions and the difficulty in navigating it. This scale ranges from 1 (very easy) to 6 (almost impossible). The levels are known as 'class' or 'category'. The time it takes to go fast can vary from a few seconds to almost a minute.

Class I – "Relaxing"
Gently moving water with small waves and no serious obstacles. Not much maneuvering necessary.

Class II – "you'll probably get splattered"
Waves are bigger and more Frequently, up to 3 to 4 feet tall. Simple movement is necessary to avoid rocks or other obstacles.
A great example of Class II and is the perfect family rafting Cheakamus River, Whistler, BC.

Class III – "You will get wet!"
Many rapids and large waves of less predictable, some may be 6ft approx. there may be minor drops or falls. Requires more maneuvering the raft. This is where true whitewater begins.
Class II-III gems are: Green River, Whistler, BC and Kananaskis River, Alberta

Class IV – "You get wet!"
Lots of high, irregular waves and long rapids. There will be rocks to avoid. Difficult conditions that require exploration.
Fun Class IV experiences: Elah-Squamish River, near Whistler, BC and Cannon Horseshoe in the Bow River, Alberta.

Class V - "A little fear – just for adrenaline junkies"
Fast Very difficult, long and violent. Large waves often unavoidable. Extremely difficult and dangerous conditions.

Class VI – "Are you nuts?"
Unraftable. Almost never attempted.

Remember though, this scale is only a guide and conditions at any huge change in different seasons rivers and can even change significantly during the night.

Although high water usually makes rapids more difficult and dangerous, sometimes it actually makes a river easier because some of its features can get coverage.

Keen to do a whitewater rafting trip?

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Check out Whistler whitewater rafting and Banff whitewater rafting tours here.

Kayaking at the New Zealand White water Slalom Nationals