by William McGinnis

“Whatever you do, Lou, don’t miss that eddy!” It was 1963; Lou and I were 15-year-old river-guide trainees on the South Fork American; and these were the words of our mentor and boss Bryce Whitmore, one of California’s first two rafting outfitters. The rapid before us–Devil’s John (now called Satan’s Cesspool and rated class III after countless successful runs over the years)–had never been run and was considered a mandatory portage/line. The plan was to run a series of back-cresting waves in the long, fast approach, and then catch that crucial eddy on the right. From there we would get out and line the boats (float them through empty, controlling them with lines from shore) through the crux of the rapid: A tight, plunging, vortex-like S-turn, where the entire river pinches, spins and plunges as though flushing down an enormous toilet. As Lou and I watched, Bryce finessed his boat through the big waves and caught the eddy perfectly. Next it was our turn.

With knees shaking and hearts pounding, Lou and I pushed the trainee boat, a black neoprene World War II basket boat with low gunnels and zero bow/stern up-kick, out into the current. Lou, the more skilled and experienced of the two of us, took the oars while I held on in the bow with white knuckles. Lou pushed on the oars portegee-style easing us through the calm and down into the rapid’s long, fast runway entrance. Lou took the first two back-cresting waves straight bow on, then did a double-oar turn to angle our bow to the left (and stern to the right), and began frantically pulling on the oars, working his entire body like a giant piston, to develop momentum into the eddy on the right. Lou’s timing was good and it looked like we would make the eddy!

Then all hell broke loose! Waves crashed in swamping the boat; Lou’s oars started to flail; an oar popped off its thole pin; and the boat spun out of control! We scrambled to get the oar back on its pin, but it was too late!! We were already careening past the eddy down into the vortex-like maw of Devil’s John, which for all we knew would swallow us whole and suck us down to Hades itself! What happened next was a complete blur of flying foam and violently convulsing neoprene, but moments later we were flushed like half-drowned rats out into the next calm utterly amazed to be drawing breath, in the boat, right side up!

This true tale is no doubt an odd way to begin an explanation of eddy catching, but at least you’ve read this far!

Eddy characteristics: Found immediately downstream from outjuttings of bank and obstructions which rise above the river’s surface, and on the inside of bends, eddies are places where the river current either stops or turns to flow upstream. An eddy’s current tends to be strongest at its top or upstream end, and weakest at its tail or downstream end where, generally, the eddy gradually peters out. The often sharp boundary at the edge of an eddy between two currents of different velocity or direction is called the eddy fence, wall or line. Usually marked by swirling water and bubbles, eddy fences on big and high water are often formidable obstacles capable of flipping boats.

Why use eddies? Eddies make great places to stop and rest; rescue, photograph or simply wait for following boats; reconnoiter downstream; recover from mishaps; etc., and, sometimes by skimming the lower end, to slow down, drop unwanted momentum and gain time. The higher one goes on the difficulty scale, the more important this river feature becomes: Using eddies is helpful on class III, crucial on class IV, and absolutely vital and essential on class V. In fact, if you’re not using eddies on class V, everything comes at you way too fast, propelling you into constant trouble.

Two basic methods for catching eddies:

Momentum Method: Start early and wide, that is, initiate your move well upriver with plenty of river width between your boat and the target eddy. Get a ferry angle (angle your boat to the current) and power toward the eddy. Allow for the moving current by aiming far enough above the eddy so that, by the time you’ve crossed the intervening water, your boat slams across the eddy fence into the top of the eddy just below the eddy-causing obstruction. The timing for this can be tricky, and it is often necessary to stop stroking and glide for a moment or two, to keep your boat from bouncing off the eddy-causing obstruction, thereby missing the eddy.

Depending on the situation, both upstream (slower than the current) and downstream (faster than the current) ferries can be used, but downstream ferries are generally favored, especially when big momentum is needed to break through strong fences.

When catching eddies using this method, paddle boats generally power forward with bow angled downstream moving faster than the current, picking up momentum to punch across the eddy line. Oar boats choose between going bow first while portegeeing (pushing on the oars), or turning around to go stern first in order to utilize the more powerful pull stroke, in the manner attempted by Lou in the historic run described above.

Slow-Pass, Quick-Move Method: First, slide closely past the eddy-causing obstruction as slowly as possible. Then, to quickly jog your boat into the eddy, swing your upstream end, which could be your bow or stern, into the eddy and apply a burst of power to scoot the entire boat across the eddy line. Remember: momentum is commitment: the less speed, the less momentum, the easier it is to quickly change the boat’s direction. Hence the importance of passing the obstruction as slowly as possible.

A typical paddle-boat “slow-pass, quick-move” eddy catch might look like this: As the boat passes, say, bow-first just to the left of a big eddy-causing rock, the crew back paddles like crazy to slow the boat as much as possible. Then, just as the stern clears the rock, the captain simultaneously leans out to do big draw strokes to pull the stern into the top of the eddy while yelling, first, “Left back!” (which means ‘left side only back paddle’–this helps both slow the boat and swing the stern into the eddy) and then, “All back!” (which means ‘everyone back paddle’–this, ideally, combined with the captain’s draw strokes, pops the boat across the eddy line).

Likewise, an oar-boat version of this method might go as follows: As the boat slides bow-first toward the water passing, say, just to the left of a big, eddy-causing rock, the oar person vigorously pulls on the oars to slow the boat. With careful timing, just before the boat closely passes the rock, the right oar blade is shipped (folded in) forward. (Take great care not to jam the blade against the rock, or the oar could get launched back at you like a javelin, which is not good!) Meanwhile, as the boat passes the rock, continuing pull strokes with the left oar both slow the boat and swing the stern to the right, toward the eddy. The moment the right oar clears the rock, with the stern already pointing right into the eddy, the oar person delivers a powerful burst of pull strokes using legs, back and arms to thrust the boat across the eddy line.


The goal of all these techniques is to completely cross the eddy fence and fully penetrate the eddy. Once inside, remember to savor the sudden contrast between the tumult of the rapid and the tranquility of the eddy. Expand, draw deep breaths, take in the rich colors, textures and shapes around you, especially the elemental magic of the liquid-diamond water. You’re alive! You belong here!


A Few Eddy Notes:

  • Losing people overboard when crossing eddy lines is common but avoidable. To minimize swims, forewarn your crews that the leading downstream corner of the boat tends to get sucked down when entering eddies, and the leading upstream corner gets sucked down when leaving. Also, just before crossing eddy lines, yell, “Lean in!” “Buns up!” (put weight on feet and lift fanny) and/or, “Hold on.”
  • When powering across eddy lines, during the brief time when the boat straddles two currents there is a tendency to spin and lose one’s angle. You can counter this and better hold your angle by applying power only on the upstream side–while crossing the line–when entering eddies, and applying power only on the downstream side–while actually crossing the eddy line–when leaving. Once the boat has fully crossed the line and is no longer straddling two currents, apply power normally.
  • In high, big and fast water, eddy fences can become major obstacles and flip boats. Generally, the best way to cross powerful fences is to hit them squarely (with the long axis of your boat perpendicular to the fence) with plenty of momentum.
  • Generally, the most efficient way to leave most eddies is to move at right angles to the eddy current, taking the shortest, most direct route to the eddy line and downstream current beyond. Exceptions to this often occur in big, high and swift water, where the extreme difference between the eddy and downstream currents can create violent fences which can be very difficult for rafts to cross. The best way to escape such an eddy is often, starting at the eddy’s tail, to power up the length of the eddy and burst across the eddy line at the very top of the eddy. (Definitely forewarn the crew that the leading upstream corner will be sucked down as the boat crosses the eddy line.)
  • Learn to spot eddies from well upriver. Even when the eddy itself is obscured from view, it is often possible to “see” eddies based on the presence of eddy causing obstructions such as bends, outjuttings of river bank and big boulders rising up out of the river. Also, beware of false eddies: Often found just downstream from trees and bushes in the current, and blade-like rocks, false eddies look like true eddies but actually are places with swift downstream current and a smooth surface.
  • Currents of different speeds and directions provide very different levels of resistance or pressure on oar and paddle blades. Sometimes, the difference is so great that a rower dipping an oar in an eddy can be knocked off their seat or have the oar handle ripped out of their grasp. The wider “wingspan” of oarboats often means the oars span different currents. At such times, take faster, deeper strokes in water providing less resistance and shallower, slower strokes on the side providing more resistance. Sometimes the pressure is so strong, just holding an oar or paddle blade stationary sea-anchor-like can take all of one’s strength–and sometimes this alone produces the desired results.
  • Of particular note to novice guides: A boat straddling an eddy line will turn effortlessly in the direction favored by the two currents, but is nearly impossible to turn the other way. As a general rule, go with the flow.


Bill McGinnis’ book  The Guide’s Guide Augmented is the definitive how-to book on professional guiding, The Guide’s Guide Augmented has the latest scoop on safety, rescue, entertainment, guide training and much more.