Rating
Most locations documented on Ropewiki are canyons or underground canyons (caves), but you may also occasionally find other locations of interest such as via ferratas and amazing hot springs. Each location is displayed with a different icon to make it easier to distinguish them, but you can also filter out the ones you are not interested in.
= Non-Technical Canyoneering
= Technical Canyoneering / Canyoning
= Caving
= Via Ferrata
= Point of Interest
Please note that while in America we consider all slot canyons (technical or not, dry or wet) proper "Canyoneering" routes, in Europe they typically don't consider it "Canyoning" unless it requires a rope and has running water.
There are two standards for rating canyons: ACA and French. Ropewiki supports both and will convert from one to the other automatically when needed, converted ratings will be displayed in Italics.
ACA Rating System
The American Canyoneering Association created a rating system for canyons that has become the standard in North America.
Format
A standard ACA rating, such as "4B IV", consists of three pieces of information regarding the technical requirements, water challenges, and time commitment of the canyon. Some variations add additional information such as extraordinary risks and rock climbing rating. Many of these ratings are subjective and different beta authors may select different ratings. There's been much controversy on the ACA water rating classification.
Technical rating
The first number in an ACA rating denotes the degree of technical skill (especially rope work) required to complete the canyon successfully.
- 1: A hike on a path with no special physical obstacles (though navigation may be difficult)
- 2: Scrambling and/or easy climbing required, but no ropes are necessary. Many groups may want a rope or webbing length for convenience, however
- 3: Technical canyon requiring ropes and rappelling and/or ascending
- 4: Extra challenge(s) beyond the obstacles encountered in most class 3 canyons. These may include very long drops, hanging rebelays, unusual exposure, or other difficulties
Water rating
Description
The letter following the technical ACA rating denotes the type of challenge presented by water in the canyon.
- A: Normally dry or very little water. Dry falls. Water, if present, can be avoided and/or is very shallow. Shoes may get wet, but no wetsuit or drysuit required.
- B: Normally has water with no current or very light current. Still pools. Falls normally dry or running at a trickle. Expect to do some deep wading and/or swimming. Wetsuit or drysuit may be required depending on water and air temperatures.
- C: Normally has water with current. Waterfalls. Expect to do some deep wading and/or swimming in current. Wetsuit or drysuit may be required depending on water and air temperatures. Class C canyons may be rated more precisely using the following system:
- C1: Normally has water with light to moderate current. Easy water hazards.
- C2: Normally has water with strong current. Water hazards like hydraulics and siphons require advanced skills and special care.
- C3: Normally has water with very strong current. Dangerous water hazards. Experts only.
- C4: Extreme problems and hazards will be difficult to overcome, even for experienced experts with strong swimming skills.
Changing conditions
Water level in any canyon can fluctuate greatly from year-to-year, season-to-season, even day-to-day. If, upon arrival at a canyon, you discover the water volume/current is greater than indicated by the rating, descent will be more difficult than suggested by the route description. It will be necessary to reevaluate your decision to attempt the descent.
Interpretation
The water ratings above were extracted word for word from page 2 of the ACA RATINGS PUBLICATION). They have been subject to much controversy because of their ambiguity in the case of a 'Low flow' canyon ('a3' in the French rating) and lack of a clear definition of 'current'. To resolve this ambiguity, canyoneers should use the idea of 'consequence' as described by Rich Carlson (original lead developer of the ACA rating system):
In my courses I describe Class A as a canyon that has no water or no water of any consequence. Class B as a canyon with water, but no current or no current of any consequence. Class C as a canyon with current that has potential consequences. (link)
I've been in Class A and got my feet wet. That was not water of any consequence. If I have to swim, the canyon can't be rated A because there are consequences if the water is cold and I didn't bring a wetsuit or I am not able to swim. Same kind of logic should apply when going from B to C.(link)
If the flowing water creates any kind of additional challenge or risk, it can't be rated B. (link)
Rating something higher than C1 should suggest that a person needs at least a little swiftwater skill or at least the ability to recognize hydraulic hazards. (link)
That same flow running over a different rock formation could create a syphon, or an undercut, etc. It's not the amount of flow that makes it C1. It is the absence of hydraulic problems. (link)
I'm sure you all understand even the term "consequences" can be subjective. I had no heartburn with Chris rating canyons B that had flow when the water was ankle-shin deep during the rappel and shin-thigh deep in the pool at the bottom. But watch some of your partners as they rappel in waterfalls that hit them in the chest. They struggle to see where they are placing their feet and struggle harder to remain upright. So even in the absence of significant current, force or hydraulic problems, those flows can have consequences beyond what is encountered in Class B. (link)
5 CFS in one canyon can be incredibly difficult while 50 CFS in another might be quite easy. C1, C2, C3 and C4 were meant to be a little vague because they were never intended to be tied to a CFS level for the reason already mentioned. (link)
CFS is comprised of 3 variables -- width, depth and velocity. Would you rather be in a stream running at 50 CFS that is 20 feet wide or 2 feet wide? (link)
Discussions
There have been many discussions regarding the interpretation and application of the ACA water rating. A few are listed below.
- Water reference level, as compared to ACA rating
- Whether a rating of B/C should be added to RopeWiki
- Poll for how canyoneers would rate hypothetical low-flow canyons
- Water condition options
- Rating of San Antonio Falls
Time rating
The roman numerals following the water ACA rating indicate approximately how long the entire canyon trip generally takes a typical group to complete. Actual time required can vary substantially in either direction, but this value is a guideline for distinguishing long canyons from short canyons.
- I: A few hours [<2h]
- II: Around half a day [2h-4h]
- III: Most of a day [4h-8h]
- IV: A full day with a prompt start [>8h]
- V: More than one day
- VI: Many days; an expedition
Extra information
Some beta authors will append a movie-style R or X to the ACA rating indicating that extraordinary risks of different degrees exist in the canyon. Also, some ratings will also include a rating for the difficulty of climbing required by the canyon in the Yosemite Decimal form (5.11a, for instance)
The allowed values for this property are:
- (blank): No extraordinary risk
- PG (or R-): Some extraordinary risks, may be hard for beginners
- R: Risky, not recommended for beginners
- X (or R+): Extreme, only for experts
- XX: Double extreme, life-threatening even for experts
External links
- ACA description of rating system
- ACA ratings from Chris Brennen
- Rating system description from Tom Jones
- Rating system description from Tanya Milligan
French Rating System
The French Federations ("Fédération française de la montagne et de l'escalade" and "Fédération française de spéléologie") created a rating system for canyons & caves that has become the standard in Europe and the rest of the world that follows the French canyoning school.
Format
A standard French rating [1], such as v3a3 III, consists of three pieces of information regarding the technical requirements, aquatic challenges, and time commitment of the route. Many of these ratings are subjective and different authors may select different ratings.
- Siphon: a constricted passage flooded with water that requires to hold the breath in order to traverse. Also called "sieve" or "sump".
- Technical jump/toboggan: dangerous jump/toboggan with problematic start, trajectory and/or landing that may have disastrous consequences if not executed properly.
The FFME lists the following assumptions in the grading of canyons:
- An average water flow for the usual season that the canyon is normally descended
- Determined by a group of 5 people, who have not been in the canyon before, but have suitable experience and skills to descend the canyon
- The level of difficult is set by at least one of the situations in the table being found in the canyon. (eg. if ANY of the v4 qualities exist at any point in the canyon, the canyon is rated v4)
- The jumps are considered optional
Vertical rating
The number following the 'v' in the French rating denotes the degree of technical skill (especially rope work) required to complete the canyon successfully.
- v1: Rope normally unnecessary for progress. No climbing or down-climbing.
- v2: Easy rappels up to 10m (30ft). Easy climbing or down-climbing with little exposure.
- v3: Simple rappels up 30m (100ft) in weak water flow. Potentially tricky hand-line traverses and down-climbs.
- v4: Big rappels of more than 30m (100ft) in weak to moderate flow. Bottom of rappel out of sight or in turbulent pools. Simple multi-stage rappels. Moderate risk of getting ropes stuck. Exposed climbs.
- v5: Difficult rappels in moderate to strong water flow. Multi-stage rappels with hanging stations or redirects. Rope recovery difficult. Difficult and/or exposed climbs.
- v6: Very difficult rappels in very strong water flow with possible hydraulics or siphons at the bottom. Awkward rappels stations, difficult traverses, exposed and difficult climbs.
- v7: Extremely difficult rappels in very strong water flow with powerful hydraulics or siphons at the bottom. Extremely difficult or risky climbs.
V4
Aquatic rating
The number following the 'a' in the French rating denotes the type of challenge presented by water in the canyon.
- a1: Dry or walking in calm water that will require no mandatory swims, jumps or slides.
- a2: Calm water. It may require swims of up to 10m (30ft), jumps of up to 3m (10ft) or easy toboggans.
- a3: Weak current. It may require swims of up to 30m (100ft), jumps of up to 5m (15ft) or moderate toboggans.
- a4: Moderate current. It may require prolonged immersion in water, jumps of up to 8m (25ft), long and steep toboggans or easy siphons up to 1m (3ft).
- a5: Strong current with avoidable water hazards. It may require prolonged immersion in cold water, jumps of up to 10m (30ft), technical jumps up to 8m or easy siphons up to 2m (6ft).
- a6: Very strong current with unavoidable water hazards. It may require jumps of up to 14m (45ft), technical jumps up to 8m or easy siphons up to 2m (6ft).
- a7: Extremely dangerous water hazards that will be difficult to overcome. It may require jumps over 14m (45ft), technical jumps over 10m (30ft) or technical siphons with strong current or poor visibility.
Commitment/Duration rating
The roman numerals in the French rating indicates commitment/duration. Duration is approximately how long it will take the entire canyon trip for a typical group to complete. Commitment is used to distinguish what canyons can be easily escaped in case of flood or medical emergency. Most books and websites use this numeral to indicate commitment level ONLY, while specifying separately the duration for approach, descent and exit in hours/minutes.
- I: A few hours [<2h]. Ability to escape flash flood easily and quickly. Easy exits present in all portions of the route.
- II: Around half a day [2h-4h]. Ability to escape flash flood in ¼ hour. Escapes no more than ½ hour apart.
- III: Most of a day [4h-8h]. Ability to escape flash flood in ¾ hour. Escapes no more than 1 hour apart.
- IV: A full day with a prompt start [>8h]. Ability to escape flash flood in 1 hour. Escapes no more than 2 hours apart.
- V: Between one and two days. Ability to escape flash flood in 2 hours. Escapes no more than 4 hours apart.
- VI: More than 2 days; an expedition. Ability to escape flash flood takes over 2 hours. Escapes are more than 4 hours apart.
External links
- French Federation description of rating system (in French)
- French rating system from Chucky (kiwicanyons.org)
- French rating system from Kevin Swanson (bccanyoneers.com)
Conversion between systems
Below is the logic used to convert between ACA / French rating systems and how to use these ratings to report conditions.
| TECHNICAL | Not Technical | Very Easy | Easy | Moderate | Difficult | Very Difficult | Extremely Difficult |
|---|---|---|---|---|---|---|---|
| ACA Technical rating: | 1 or 2 | 3 (r<30ft) | 3 (r>30ft) | 3 PG or 4 | R | X | XX |
| French Vertical rating: | v1 | v2 | v3 | v4 | v5 | v6 | v7 |
| Difficulty Condition: |  Nontechnical |
 Easy |
Easy |
 Normal |
 Special challenges |
 Advanced |
 Extreme
|
| WATER FLOW | Dry | Calm | Weak | Moderate | Strong | Very Strong | Extremely Strong |
|---|---|---|---|---|---|---|---|
| ACA Water rating: | A | B | B/C | C1 C |
C2 C R |
C3 C X |
C4 C XX |
| French Aquatic rating: | a1 | a2 | a3 | a4 | a5 | a6 | a7 |
| Water Condition: |  Dry |
 Very Low Deep pools |
 Low |
 Moderate |
 High |
 Very High |
 Extreme
|
| Caudal (Spanish) | Seco | Muy bajo Muy flojo Hilillo de agua Pozas de agua |
Bajo Flojo Escaso |
Normal Adecuado |
Alto Fuerte |
Muy alto Muy fuerte |
Muy peligroso Extremo Excesivo Imposible |
| TIME | <2h | 2h - 4h | 4h - 8h | 8h - 24h | >1 day | >2 days |
|---|---|---|---|---|---|---|
| ACA Time rating: | I | II | III | IV | V | VI |
| French Commitment/Duration rating: | I | II | III | IV | V | VI |
| NO CONVERSION FOR COMMITMENT | ||||||
Caving Rating
This is a String that represents the type of location. The allowed values for this property are:
- Cave : natural underground location, vertical (technical) or horizontal (semi-technical), wet or dry
- Pit : natural underground location, mostly vertical with not much horizontal passage, wet or dry
- Mine : man-made underground location, vertical (technical) or horizontal (semi-technical), abandoned or active
- River Cave : underground river with substantial flow, vertical (technical) or horizontal (semi-technical), usually explored with a through trip
- Resurgence Cave : surface exit of an underground river, vertical (technical) or horizontal (semi-technical),may or may not connect to other entrances
- Insurgence Cave : entrance of an underground river, vertical (technical) or horizontal (semi-technical), may or may not connect to other entrances
- Ice Cave : glacier caves, vertical (technical) or horizontal (semi-technical), wet or dry
