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Codes Used to Indicate River Difficulty

There are two systems for coding rivers that you may see on our trip schedule. Both systems are approximations of difficulty because the difficulty of a river or stream can change dramatically with weather and water levels.  These codes give you the relative difficulty of a given stream, but not the absolute difficulty, and they are not a substitute for knowledge and experience. 
If you are unfamiliar with the advertised trip you should consult guidebooks or the American Whitewater National River Database. There are many websites that post paddling information, but as with everything on the web, there is a lot of bad information out there as well as good. While you should talk to the trip coordinator before committing yourself to a paddling trip, the final decision is yours.  You are responsible for your own safety.

If you have questions about CCA trips, contact
These are the codes that you may see on our trip schedule.
Code Description Whitewater Class
N Novice Class I
PN Practiced Novice Class I/II
LI Low Intermediate Class II/III
I Intermediate Class III
HI High Intermediate Class III/IV
A Advanced Class IV
E Expert Class V
Below is an excerpt from the American Whitewater Safety Code, which explains the river class system.  All paddlers should be familiar with the AW Safety Code.  If you paddle the more difficult rivers and streams, we highly recommend that you take a Swiftwater Rescue Class and a Wilderness First Aid class.

 International Scale of River Difficulty

This is the American version of a rating system used to compare river difficulty throughout the world. This system is not exact; rivers do not always fit easily into one category, and regional or individual interpretations may cause misunderstandings. It is no substitute for a guidebook or accurate first-hand descriptions of a run.

Paddlers attempting difficult runs in an unfamiliar area should act cautiously until they get a feel for the way the scale is interpreted locally. River difficulty may change each year due to fluctuations in water level, downed trees, recent floods, geological disturbances, or bad weather. Stay alert for unexpected problems!

As river difficulty increases, the danger to swimming paddlers becomes more severe. As rapids become longer and more continuous, the challenge increases. There is a difference between running an occasional class-IV rapid and dealing with an entire river of this category. Allow an extra margin of safety between skills and river ratings when the water is cold or if the river itself is remote and inaccessible.

Examples of commonly run rapids that fit each of the classifications are presented in the attached document, "International Scale of River Difficulty - Standard Rated Rapids." Rapids of a difficulty similar to a rapids on this list are rated the same. Rivers are also rated using this scale. A river rating should take into account many factors including the difficulty of individual rapids, remoteness, hazards, etc.


The six difficulty classes:


Class I Rapids


List of Class I thru III Rated Rapids


Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.



Class II Rapids: Novice


List of Class I thru III Rated Rapids


Straightforward rapids with wide, clear channels which are evident without scouting. Occasional maneuvering may be required, but rocks and medium-sized waves are easily missed by trained paddlers. Swimmers are seldom injured and group assistance, while helpful, is seldom needed. Rapids that are at the upper end of this difficulty range are designated “Class II+”.



Class III: Intermediate


List of Class III Rated Rapids


Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe. Complex maneuvers in fast current and good boat control in tight passages or around ledges are often required; large waves or strainers may be present but are easily avoided. Strong eddies and powerful current effects can be found, particularly on large-volume rivers. scouting is advisable for inexperienced parties. Injuries while swimming are rare; self-rescue is usually easy but group assistance may be required to avoid long swims. Rapids that are at the lower or upper end of this difficulty range are designated “Class III-” or “Class III+” respectively.



Class IV: Advanced


List of Class IV Rated Rapids


Intense, powerful but predictable rapids requiring precise boat handling in turbulent water. Depending on the character of the river, it may feature large, unavoidable waves and holes or constricted passages demanding fast maneuvers under pressure. A fast, reliable eddy turn may be needed to initiate maneuvers, scout rapids, or rest. Rapids may require “must” moves above dangerous hazards. Scouting may be necessary the first time down. Risk of injury to swimmers is moderate to high, and water conditions may make self-rescue difficult. Group assistance for rescue is often essential but requires practiced skills. A strong eskimo roll is highly recommended. Rapids that are at the lower or upper end of this difficulty range are designated “Class IV-” or “Class IV+” respectively.



Class V: Expert


List of Class 5 Rated Rapids


Extremely long, obstructed, or very violent rapids which expose a paddler to added risk. Drops may contain** large, unavoidable waves and holes or steep, congested chutes with complex, demanding routes. Rapids may continue for long distances between pools, demanding a high level of fitness. What eddies exist may be small, turbulent, or difficult to reach. At the high end of the scale, several of these factors may be combined. Scouting is recommended but may be difficult. Swims are dangerous, and rescue is often difficult even for experts. A very reliable eskimo roll, proper equipment, extensive experience, and practiced rescue skills are essential. Because of the large range of difficulty that exists beyond Class IV, Class 5 is an open-ended, multiple-level scale designated by class 5.0, 5.1, 5.2, etc… each of these levels is an order of magnitude more difficult than the last. Example: increasing difficulty from Class 5.0 to Class 5.1 is a similar order of magnitude as increasing from Class IV to Class 5.0.



Class VI: Extreme and Exploratory Rapids


These runs have almost never been attempted and often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are very severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions. After a Class VI rapids has been run many times, its rating may be changed to an apppropriate Class 5.x rating.