Understanding Whitewater Classifications
Developed by the American White Water Association, the International River Grading System classifies river segments around the world according to their difficulty. It indicates the skill level needed and technical challenges related to each river section to help paddlers prepare. Whitewater classifications are not only utilized by whitewater rafters but also by kayakers and canoeists.
Whitewater rafting levels of difficulty
Rapids are categorized into six distinct groups, each known as a "Grade" or "Class." It's important to understand that the grade/class of a river can fluctuate with the flow level, and some rapids sharing the same grade may present varying levels of difficulty. Occasionally, these differences are marked with a + or - sign.
Keep in mind that while a whole section of the river is classified under a specific grade or class, it can still include brief stretches that fall above or below that classification.
Most of our guides prefer to use the term "class" instead of “grade”, although they can be used interchangeably.
To learn more about common whitewater rafting terms, check out our lingo guide here.
Class/Grade I Rapids
Swiftly flowing water with gentle waves and minimal hindrances, providing a relaxing way to enjoy a river and its beautiful surroundings.
Class/Grade II Rapids
Gentle rapids with predominantly wide channels that are easy to navigate. They may include rocks and medium-sized waves that are unlikely to capsize a boat, making for a fun and exciting experience.
Class/Grade III Rapids
Moderately challenging rapids with waves that can jostle the boat and require attentive paddling, though they are generally easy to avoid. Some tight spots demand precise navigation, and strong eddies and powerful currents may call for more advanced maneuvers.
Class/Grade IV Rapids
Strong yet fairly predictable rapids, featuring narrow channels and choppy waters that demand careful navigation. Quick reflexes and swift maneuvers may be necessary at times to negotiate large, unavoidable waves, calling for an experienced guide. If a guide is not acquainted with specific Class IV rapids, they will usually pause to assess the rapid before attempting it.
Want to find out more? Check out our guide featuring three of the top class IV rivers in the USA.
Class/Grade V rapids
With all the difficulties of Class IV Rapids, combined with significant drops and narrow chutes, Class V rapids guarantee an adrenaline-pumping experience. These rapids often feature big waves, rock gardens, and turbulent eddies that are hard to access and extend over vast stretches, testing the stamina of paddlers. Previous rafting experience and hands-on rescue abilities are essential.
Class/Grade VI Rapids
Rivers with Class VI rapids are frequently labeled as "un-runnable" and should only be attempted by highly skilled paddlers. They are unpredictable and pose significant dangers, making them unsuitable for outfitter rafting excursions. Rescues around Class VI rapids can be nearly impossible and mistakes can lead to serious consequences.
The Grand Canyon
The Grand Canyon has its own rating system (from 1 to 10), which was assigned to its rapids prior to the establishment of the International River Grading System. For reference, a Class 10 rapid on the Colorado River corresponds to a Class IV rapid on the international scale.
Selecting the perfect river trip
From the scenery to the season and the duration of the trip, there are many factors to consider when selecting a river that suits you best. The difficulty level of the rapids is important to consider, and before you commit to a river rafting adventure, it’s essential to understand the classification system and its implications.
Think about your paddling experience, how much risk you’re willing to take, and the thrill you’re after before selecting a river trip. When making your choice, don’t forget to take into account the experience levels of your family and/or travel companions to ensure the adventure is memorable for everyone involved. As a rough guide, most rivers favored by rafters fall within Class/Grade II to IV according to the International River Grading System.
When planning your trip, keep in mind that water flows vary with the seasons, meaning that high or low water levels can change the classification of certain rapids at different times of the year. Generally speaking, high water tends to make rapids more challenging, although some may become easier as obstacles are submerged or washed away.
On the other hand, some rapids can become more technical when the water is lower and will present a different kind of challenge compared to high water conditions.
If you're uncertain about which rafting adventure suits you best, feel free to chat with one of our Adventure Consultants. With more than 60 years of combined experience in sales and rafting, they possess a vast amount of knowledge and can align your experience level and interests with the perfect trip.
