A glossary of whitewater terms to get you ready for river SUP

The first step in becoming proficient at paddling swift-moving water and whitewater is learning the language of the river. Think of the rapid as a puzzle—the better you understand it, the better you'll be able to navigate it. When you start understanding the way water moves, you can apply your paddling skills to the different features, set your angle, maintain forward momentum and stick your line down more complex rapids. Once you start, you won't want to stop.

The tongue
This is your entry into the rapid. Also known as the "V," this is where the river speeds up and approaches the first obstacles in a rapid. The water is deepest here and, generally speaking, you want to start your line by entering the rapid with a couple hard strokes to get your speed up.

Wave trains
In a straightforward rapid, once you enter once you enter through the tongue, you'll hit the wave train, which is a family of successive waves, usually with the biggest first, then descending in size. The first wave may be the roughest and zap a lot of your speed, necessitating some brace and forward strokes to make it through the successive ones. Punch your nose straight into waves to maintain stability. Some waves with longer, cleaner troughs can provide river surfing opportunities if formed correctly. Others may be too steep or have too big of a foam pile. A recirculating wave that's all foam pile is a retentive obstacle, often called a hole, that should be avoided.

Eddies and eddylines
Eddies are created by obstacles (bends in the river, rocks) that block the current, and create pools on the downstream, leeward side where water can circulate back upstream. Where the downstream current and the slack or upstream flow meets is called an eddyline. Many spills happen here because opposing forces pull on your rails. Look for eddylines at the rippling edges of the main current or behind obstacles. Maintain momentum into and out of eddies and try to enter and exit at 45-degree angles.

A pillow forms when the river's current pushes against a rock and barely pushes over it, creating a bulge of water. When you see a lone wave, give it a second thought. This usually means there's a submerged "sleeper" rock underneath to be avoided.

Pools are your sanctuaries after rapids, formed when gradient decreases and the riverbed deepens and slows.

If you're lucky, the shoulder of the river or an island in the middle will provide easy passage to walk around an un-runnable rapid, or, even better, following one that you'd like walk up and run again.

Make sure you always wear a helmet, life jacket, insulating layers for the water temperature, close-toed foot protection and an appropriate quick-release leash attached to your life jacket (never on your ankle). Start slow and learn swiftwater rescue basics by paddling with river veterans. –WT

Photo by Aaron Black-Schmidt, design by Marc Hostetter.

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