By William McGinnis

Adrenaline pumping, heart pounding, you speed down into huge holes alive with upwelling mountains of erupting white popcorn foam. The exploding foam overwhelms and stalls and knocks your boat for a loop, inundating your raft, slamming and lifting your bow paddlers. You yell, “Dig, dig, dig! Forward! Forward! Need ya now! Need ya now! FORWARD!“ spurring your crew, every one of whom is stroking like a wild demon while fighting to stay braced in the boat … Need I say more? Clearly, we are talking about a ton of fun!!! To pursue this extraordinary pastime…

First, build broad skills and learn to read holes: Work your way up the difficulty scale slowly over time in the company of more experienced boaters. As you start mild and work up gradually, learn a full array of boating and rescue skills, including what size holes your boat can—and cannot—handle, and how to distinguish big, fun, runnable, flushing holes from unrunnable keeper holes.

Holes are places where the current, generally after accelerating downward, swings upward and revolves back on itself, often in the form of steep back-cresting waves or sometimes in the form of flat, foamy, surface back flows. In big holes, the flow often blasts in at an incline and explodes in an awesome back-cresting wave, with some of the white foam exploding in place and some blasting on through. The more foam blasting on through compared to the amount of foam merely exploding in place, the more likely the hole is to be runnable. In my experience, holes where the flow enters at an incline of less than 45 degrees, are more likely to have a higher portion of foam blasting on through, providing what some call “stabilizing surface blow through”–and hence, are more likely to be runnable.

On the other hand, holes below vertical water falls, although often flat and seemingly less violent, are more likely to be unrunnable because there is no stabilizing surface blow though. Instead, all the foam on the surface is flowing back upstream into the vertical face of the falls, forming a treacherous keeper that can hold and flip boats and entrap and tumble swimmers.