For my white water instructors degree training I was asked to provide some films or photos that describe the different white water classes or categories that are classified. For this training we will have a workshop day next year in 2011 looking at basic whitewater safety and rescue, like lines to kayak in a rapid and how to throw a throw rope to rescue a swimmer. The provided videos and photos will be used on this day for some exercise I don’t know about yet.
As this might be interesting for more people, I decided to blog about it instead of just putting it in a document for the instructor. As I will need some time for each class, I will blog in multiple articles each focusing on one class.
I have a basic understanding of the white water classes, but before I can start acquiring these photos or videos I first need to know how the classes are classified. According to the wikipedia article on white water, the most widely used grading system is the “International scale of river difficulty” that classifies a stretch of white water into 6 classes, with roman numerals, from I to VI. A difficult class III can be classified with a + sign to indicate the difficulty, an easy IV could be IV- to indicate it.
There are six levels each referred to as “Grade” or “Class” and then a number. The scale is not linear, nor is it fixed. For instance, there can be hard grade twos, easy grade threes, and so on. The grade of a river may change with the level of flow. Often a river or rapid will be given a numerical grade, and then a plus (+) or minus (-) to indicate if it is in the higher or lower end of the difficulty level. Also note that while a river section may be given an overall grading, it may contain sections above that grade, often noted as features, or conversely, it may contain sections of lower graded water as well. Details of portages may be given if these pose specific challenges.
The above description is from the wikipedia article on “International Scale of River Difficulty“. Apparently there are more classifications, the article itself mentions Australia and New Zealand, India and the USA as three different variations on the international scale. Maybe I will look into that for another post.
In the next post I will start looking at Class I and start looking for media that describe it visually.