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Aqua Shack
449 Boston Post Rd. East (Route 20)
Route 20, Marlboro, Mass. 01752
(508) 229-7707
- Only 3.25 miles East of Route 495
Email: captjim@aquashack.com
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Measure
Your Ecological Footprint
One Love,
One Destiny.
One Earth,
One CHANCE!
Symbiosis.
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International Scale of River Difficulty
As one might expect, the difficulty of a particular paddling trip (like the difficulty of any particular dive) is dependant on many factors: discharge rate (on dam controlled rivers), gradient, complexity of rapids, the types amd frequency of obstacles and immidiacy (or difficulty) of rescues are amoung some of the more obvious. Any one of these could dominate and make the trip tougher; it is necessary to consider them all. How, then, do we objectively make a quantitative rating of difficulty? The quick answer is, it's not easy! However, over the years an international system of of grading rivers or individual rapids, on a scale of I to VI, has evolved to be the most frequently used and is the system used here.
An unofficial description of the six classes of rapids follows. It is a hybrid of many descriptions found in various publications. Although differing in wording and some small details, most of these are quite similar overall. The following descriptions are intended to capture the spirit of the system.
| Fastwater or Quickwater |
EASY- Moving water with few or no features. Large clear passages; no serious obstacles; self-rescue is very easy (for example a short swim to an easily accessible shoreline). |
| CLASS I |
EASY- Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with a little training. Risk to swimmers is slight and self-rescue is fairly easy (land may be a slightly longer swim or more difficult to get up on due to current or slope of riverbanks.) |
| CLASS II |
MEDIUM - Rapids of moderate difficulty with passages
clear. Most open canoeists should never tackle anything tougher
than class II. |
| CLASS III |
DIFFICULT - Rapids are longer and rougher than
class
II. Waves numerous, high, irregular; rocks; eddies; rapids
with passages clear though narrow, requiring expertise in
maneuver; scouting usually needed. Requires good
operator and boating equipment. |
| CLASS IV |
VERY DIFFICULT - Rapids are generally longer,
steeper and more heavily obstructed than class III
rapids.Waves powerful, irregular; dangerous rock; boiling
eddies; passages difficult to scout; scouting mandatory first
time; powerful and precise maneuvering required.
Demands expert boatman and excellent boat and outfit. |
| CLASS V |
EXTREMELY DIFFICULT - Exceedingly difficult, long
and violent rapids, following each other almost without
interuption; riverbed extrememly obstructed; big drops;
violent current; very steep gradient; close study essential,
but often difficult. Requires best man, boat, and outfit
suited to the situation. All possible precautions must be
taken. |
CLASS VI
or U |
UNRUNNABLE for almost all humans! ! ! Unless you are Tao Berman (or as good as him) and extremely LUCKY, don't even try this. Even if you are as good as Tao and LUCKY, you will probably still DIE or be crippled for life attempting this run. |
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