Whitewater Rapid Classification System

Whenever someone goes rafting or kayaking on whitewater rapids it is vital that they have a good idea of what they can expect from the river. To clarify and simplify this process, all whitewater rapids are rated on a scale of I to VI. The rapids receive ratings based on a combination of difficulty and danger, where a class I rapid is the least difficult and dangerous and class VI rapids are the most difficult and dangerous.

The classification system for whitewater rivers is not an exact science. The classifications of rivers and rapids may vary with fluctuating water levels. Typically, high water levels increase the difficulty of rapids. However, this is not always the case. Some rapids become more technical and more difficult at lower water levels. The classification system also does not take into account the type of boat being paddled. Some rapids may present particular challenges for rafts, while other rapids may be more difficult for a whitewater paddler in a kayak. Finally, as with any rating system, there is an element of subjectivity. While most commercial outfitters and experienced paddlers are able to agree on the rating of particular rapids, there will always be some who believe a certain rapid should be Class III, while others believe that it should receive a class IV rating.

Here's the disclaimer: the classification system is a guide only. Most rivers are a combination of the classifications and have varying degrees of difficulties based upon water levels. Please call us at Wet Planet if you have any questions about which rivers are appropriate for your group.

The most important thing to remember with the classification system ... it has nothing to do with how much fun a rapid is. The system is based on difficulty and danger, which do not always equate with the "fun factor" of a rapid. There are plenty of class III rapids that are more fun to raft than many class IV rapids.

At Wet Planet, we use the following internationally accepted rating system:

Class I:

Moving water with a few riffles and small waves. Few or no obstructions.

Class II:

Easy rapids with smaller waves, clear channels that are obvious without scouting. Some maneuvering might be required.

Class III:

Rapids with high, irregular waves. Narrow passages that often require precise maneuvering.

Class IV:

Long, difficult rapids with constricted passages that often require complex maneuvering in turbulent water. The course may be hard to determine and scouting is often necessary.

Class V:

Extremely difficult, long, and very violent rapids with highly congested routes, which should be scouted from shore. Rescue conditions are difficult, and there is a significant hazard to life in the event of a mishap. The upper limit of what is possible in a commercial raft.

Class VI:

The difficulties of Class V carried to the extreme. Nearly impossible and very dangerous. For teams of experts only. Involves risk of life. Class VI rapids are not commercially raftable.