Most of you are used to the commonly used scale of river difficulty, the Class III or Class V+ (etc) rating system. The problem is, it's innacurate and doesn't work very well when used across a variety of craft (rafts, kayaks, riverboards). If you want to see American Whitewater's official scale, it's here: International Scale Of River Difficulty

I ran across the Addison Scale recently and was impressed - Docta P and I have been working on our own scale for riverboarding, and world class kayaker and Corran Addison is right on the money with his scale - the only thing we'd add to it is some descriptions of the danger, but we'll get to that in Part 2. For now, what do you think about this river rating system?

Personally, I think it's far advanced beyond the old system (which, ironically, the old system prefaces everything by saying there are many exceptions to the rule - with the Addison Scale, there aren't). Give it a read and let me know what you think.

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Addison's Scale
Corran Addison’s appraisal of the current river grading system
 

(The examination of a static rating system in a dynamic sport by Corran Addison)

The problems lie in the very foundation of the system. With one number, we have attempted to describe the difficulty, element of danger and exposure. Combine this with the fact that the latest breakthroughs in equipment and techniques have allowed us to push the limits of the possible, and that the system has a cap, and we find that the last digit of class five has as wide a range of rapid difficulties as all the proceeding numbers combined.

What the system fails to see, is that the elements of danger and difficulty (the principal concerns) are not the same thing. A rapid can be dangerous, but easy to run (a wave train requiring no boat skills, but with an undercut off to one side). Another can be technically difficult, but with very little danger (a series of waterfalls into deep pools). The third and seemingly less important, though it is not, is exposure: if things go bad, how long will it take to get help? An hour; a day; a week?

Given that our sport is still young and developing, we can continue to assume that the limits of the possible are still being pushed, so to have a cap on the system places unnecessary pressure on the lower scales, or packs too many variables into one number. Considering that our sport takes us to the most desolate corners of the earth, the element of exposure is also an important one. A broken leg on a roadside run an hour from a major metropolitan area is no real concern. A broken toe in the most remote corner of Tibet is a very real concern.

As such, you are more likely to take chances on your local run than on an expedition where even if there were medical help, it would be questionable.

So an effective system would include the element of (1) Difficulty (what is the absolute minimum amount of skill needed to successfully run this rapid), (2) Danger (if I make a mistake, what are the consequences of that mistake), and (3) Exposure (once I have made a mistake, how long before I get help).

Point (1).
As stated before, it needs to be open ended. No consideration for the consequences should be used while addressing this rating. It is a pure and cold assessment of the minimum skills needed to run the rapid. It should be open ended (no cap), with the current rating difficulty used as a starting point, spread over one to ten, with the ability to add eleven, twelve and so on as needed.

Point (2) is much simpler.
Again, using our current rating system as a base, we give this a one to six assessment. One, the is almost no danger at all. Three there is the possibility of minor injury, including bone breakage, serious cuts and bleeding (basically you're in serious trouble, but death is unlikely - depending on point 3). Five there is a high probability of serious injury (spinal breakage etc.) and a very real possibility of death. Six, you die. This has a cap, as you can't be any more or less dead. The key to remember here is the Îmost likely scenario. You can drown in a small ripple, but the chances of it are so slim that it is not realistic. You might also swim out of a hole that has killed many people before you, but again in assessing the danger, you need to keep in mind that IF you swim there, you will most likely die.

Point (3) is linked to point two.
A broken rib with some internal bleeding one hour from a hospital is not a very real concern. However, a day or more from help, and now you have a problem. This is broken into three letters. A is less than an hour to receive help. B is more than one hour but less than 24 hours, and C is 24 hours or more. This rating considerably changes the importance of the first two points.

So to recap
the system reads like this. How hard is it for me to run this, and if I blow it, what'll happen to me. Some examples are: Niagara Falls 3.5A (3 for difficulty - not that hard, 5 for danger, and A for help). Five Falls on the Chattooga at 4 ft, 6.3B, and the upper Zambezi above Victoria Falls, 2.5C (easy, but if you swim you get eaten by a crock or hippo and you don't want to be treated in one of those hospitals). The effectiveness of the system is realised in the following scenario.

A class five (technically) paddler (scale 1 to 10) looking at a 5.2A. No problem. The rapid is challenging, but the consequences of a mistake are nominal, so go for it. Challenge yourself and progress. However, this same paddler looking at a 5.4C should be walking as the skills to deal with a mistake in the rapid are not there, and the consequences of the mistake are severe.

This system, which I have been using for several years (and is jokingly referred to as Addison's Scale by my paddling partners) has proven to be very effective in describing a run to paddlers familiar with it's workings. Because of its effectiveness, I am now making a push for it's international acceptance and use. Such a system (which has evolved to its present form over about ten years use and modification) could very effectively eliminate many of the problems that arise constantly from our current system.

If you support this system, please mail a letter to the effect to Corran Addison, I will use these letters of support for such a change to lobby the governing bodies all countries involved with whitewater paddle sports.

For further information about the IWF, contact Corran Addison at:

Tel/Fax: 418 - 667 0915, CP 63 St Augustin, Quebec, G3A 1V9, Canada *** *** ***

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Ok, Ice here again. 

So what do you think? Should the rating system be changed?

Here are some sample ratings that I (Ice talking now) came up with based on the Addison scale for RIVERBOARDING only (rapids change in difficulty whether you’re in a raft, kayak, or on a riverboard – so they should be rated accordingly):

Husum Falls (White Salmon, Washington) – 4.3A (class 4 difficulty, has a level 3 danger, and is less than an hour to a hospital [According to the current rating, it's a Class V)

Sweets Falls (Upper Gauley, WV) – 4.3B (class 4 difficulty, level 3 danger, more than hour to hospital) [currently called a Class V]

Roller Coaster (Wairoa, NZ) – 4.3B (class 4 technical difficulty, level 3 danger, more than an hour  - including hike out – to hospital) [rated Class V]

Nevis Bluff (Kawarau, NZ) – 5.4B (class 5 difficulty, level 4 danger, more than hour to hospital) [rated Class V+ or VI depending on who you talk to]

Citroen (Kawarau, NZ) – 4.3B (class 4 difficulty, level 3 danger, more than hour to hospital) [rated Class IV+]

Tutea Falls (Kaituna, NZ - the famous one seen on the Amazing Race) – 4.4B (class 4 skills, level 4 danger, more than hour to hospital) [currently Class V]

Would love to hear your feedback on this. I'm sure there are plenty of rapids on your local rivers that are rated considerably higher than necessary, since they were probably rated by rafters. Those ratings don't usually apply to riverboarders.

We're considering using it for riverboarding from now on with some adaptations...