Whitewater River Terms Everyone Should Know

Learn whitewater river terms! Photo by Rob Elliott.

When you climb aboard a raft with a Grand Canyon river guide from Arizona Raft Adventures, you hear them jabber on with rafting and whitewater river terms.

Some of the lingo might be familiar, but for guests it can be overwhelming. Not to mention, the guides will continue to flood you with a whole new glossary of campsite slang, paddle boat commands and terminology specific to a Grand Canyon raft adventure. Here are a few simple whitewater river terms to help prepare you for your raft adventure.

CFS

CFS stands for cubic feet per second. Cubic feet per second is the unit in which guides, rangers and other professionals measure the volume of water in the river. Check out this river gauge for the most up-to-date CFS of the Colorado River in the Grand Canyon.

Current

The current is the water’s natural flow downstream. Consequently, all the water may be flowing downstream. Look for the fastest moving water. This is called the “main” current. River guides like to find the main current to maximize the movement of downstream travel and to conserve energy.

Eddy

Eddies make for great spots to pull the boats over for a hike or for camp.  Photo by Rob Elliott.

When water flows back upstream in an area void of the current an eddy forms. They typically form along a river bank where the water has been previously deflected by an obstacle. They can vary in size. Some are barely big enough for one or two rafts, while others are a hundred yards long.  Eddies make great spots to pull in to slow down (if waiting for other rafts). They are also ideal to pull into to park for a hiking excursion or to make camp. “Eddy out” or “catch an eddy” is one of the most popular whitewater river terms.

Eddy Fence

Also known as an eddy line, the eddy fence is the swirly confused water between an eddy and the current. River water pulls different directions along the eddy fence which causes the water to be unstable. Sometimes an eddy fence pulls you into an eddy whether you want to enter it or not. Alternatively, sometimes the eddy line is hard to break through, thereby keeping you in the main current even if you try to catch an eddy.

Hole

When river water flows over a rock or a shelf and circulates back upstream a hole, or hydraulic, is created. The water is turbulent and can recirculate anyone or anything that might enter it.  This is one scary whitewater river term!

Put-In / Take-Out

Lee’s Ferry is a popular put-in location for Grand Canyon Outfitters. Photo courtesy of Catherine Wilson / Facebook.

The put-in is the access point where the boat launches at the beginning of a section of river. Lee’s Ferry is the most popular put-in location for all Grand Canyon raft outfitters. The Lee’s Ferry boat ramp is in the Glen Canyon National Recreation Area in Marble Canyon, Arizona.

The take-out is the location where the boats depart the water at the end of the section of river. If you raft with Arizona Raft Adventures, this location is called Diamond Creek. The Diamond Creek take-out is a unique location. It is only accessible by a long and bumpy drive down a remote dirt road. Therefore, it is an adventure just getting back to civilization.

Rapid

A rapid starts when river water flows over or around a series of obstacles at or below the water level.  A rapid consists of waves, holes, pour-overs, bubbly water and a quick current. Rapids in the Grand Canyon are primarily at the mouth of side canyons. Rocks and debris wash down the side canyons into the river and produce obstacles for the river current. There are about 150 rapids in the Grand Canyon between Lee’s Ferry and Diamond Creek. Each year, rubble shifts to create new or even change existing rapids. Rapids are also rated by level of difficulty. Click here for more about rapid ratings in Grand Canyon. Here is a video of one of the biggest rapids in Grand Canyon. 

Reading Water

“Reading water” refers to one’s ability to look at the river and recognize certain features. When a guide reads the water, they look for obstacles, best runs through whitewater and the fastest current which enables them to pilot a water craft in the most efficient and safe manner.

Riffle

A riffle is a very small rapid and often nothing more than a little bubbly water that flows over a shallow section of the river. Riffles are not usually named (though some are) and most pose little threat to an oar boat or paddle raft. However, if a riffle indicates a shallow obstacle, this is a hazard to a larger raft with an outboard engine.

River Right / River Left

Guides refer to river right or river left as a directional cue to look at something downstream. When you look downstream, the river right is on your right hand side and river left on your left hand side.

Strainer

Courtesy of Pennsylvania Fish and Boat Commission.

A strainer occurs when a tree, tree branch, or a large bush is in the river and the current continues to flow through the obstacle. A strainer, or “sieve”, can also be made out of rocks sticking up out of the water. This creates a “strainer” effect (like draining cooked pasta) and can be very dangerous to rafts, swimmers and other small crafts such as kayaks.

Tongue

The tongue forms at the top of a rapid where the water speeds up. The water funnels into the rough and more turbulent water. The tongue is usually easy to spot because it is smooth, glassy, and darker in color because it has less air bubbles mixed in. It is generally the location where a raft enters a rapid because it is a stable location where the raft is less likely to tip.

Wave Train

A wave train is the most fun of all the whitewater river terms! A wave train is a feature of a rapid that is a super fun series of waves. There are a lot of wave trains on the Colorado River in the Grand Canyon. They feel a lot like ocean waves and can get really big — maybe even towering ten feet over your head! Therefore, find a couple good hand holds before you enter the rapid!

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