White water rapids
From Wikipedia, the free encyclopedia
White water rapids are places where water undergoes extreme turbulence, so named because of the white appearance the water achieves. The common cause of this turbulence is rocks near the surface of the water. Fast-moving water will move up and over these rocks and cause foaming and the general white appearance as the water reflects more light than usual. Rapids are often traveled by water sportsmen and women, who go down them in canoes, rafts, kayaks and more.
Rapids are usually at their highest and most dangerous during the spring as the snow has melted and spring showers have swelled the river. This is the most active time for White Water Sports.
[edit] Categories of Rapids
There are six categories of rapids based on difficulty of traversal.
- Class 1 - Easily traveled/warm up rapids
- Class 2 - Medium difficulty of navigation
- Class 3 - Difficult, irregular and requires expert navigation to successfully travel.
- Class 4 - Very Difficult, irregular, fast and dangerous
- Class 5 - Extremely Difficult, even more dangerous, often includes near waterfall drops
- Class 6 - Completely unrunnable
There are often regulations regarding what class rapids a commercial vessel can traverse. Category 5 is usually the highest allowed.
International Ratings System:
Class I.- Easy. Smooth water with a few light riffles. Gentle curves, shallow drop, and an occasional sand bank thrown in to keep you awake.
Class II.- Moderate. Fairly swift water, rapids with regular waves, some rocks but with clear and open passages between them. No problem for paddlers with intermediate skills.
Class III.- Moderately difficult. Look for numerous high and irregular waves, rocks, and eddies. The passages are clear but narrow and can be tricky to handle. When in doubt, a visual inspection is a good idea. These rapids are best left to paddlers with good to expert skills.
Class IV- Difficult. Extended and powerful rapids with standing waves in this class. Even more challenging when boiling eddies and deep holes are tossed in. Expert paddling skills are required here, and visual inspection from shore is mandatory. And don't forget to plan for possible rescues before taking on Class IV water.
Class V- Extremely difficult. Look for long, violent rapids that extend without interruption. Steep drops, strong currents, and a river full of obstructions. This water can only be run by experts, and only after making rescue preparations.
Class VI.- Extraordinarily difficult. Even world-class paddlers take this water on with trepidation. Extreme danger here, and these rapids are only navigable when conditions and water levels are perfect. Stay away from these rapids unless you're an expert, and you're willing to risk life and limb in the attempt. And make sure to take every safety precaution available.
