Choosing to run whitewater, and doing it successfully, can have a significant impact on your next canoe trip. Jumping in over your head and running a rapid that results in an overturned boat, or worse, can ruin your trip, or at least your gear. Often your choice, and success, comes down to your ability to read water, the language of rivers, and understanding all that the river is trying to communicate to you – its’ paddling audience.
The language of rivers is composed of two main visual characteristics; texture and colour. As you moving water winding its’ way over rocks, ledges and around outcrops and around bends in the river bank, you’ll see a veritable kaleidoscope of changing colours and wave patterns. Each obstacle leaves a visual marker to it’s’ presence. By looking at the changing textures and colours you can decipher the river bottom, the level of difficulty of the water features, and ultimately, make a choice as to whether you ought to run, or not run, a rapid.
The Vocabulary: Colour and Texture:
As water tumbles over rocks, ledges and gravel bars, the distinctive roughness of each disrupts and slows the water down. Each collision alters the water surface with vortices, boils, waves, and when air mixes into the current, changes it’s colour to lighter shades of blue, green, black and brown. Every change signals a river bed or water feature that might have to be avoided by your canoe.
Reading the texture of the water includes looking at everything from large standing waves and dramatic rooster tails, right down to the small swirls and bumps often found on eddy lines. Each can be equally significant. For many, however, a rapid is first judged by the roller coaster of waves they’ll ride during their run. Beyond looking at size, navigable waves usually occur in groups, or families. Standing waves should have a minimum of three similar, evenly spaced waves decreasing in size as you look downstream. Lone wave should be approached with caution – chances are it is hiding a rock. Also, waves positioned across the flow of water are much easier to “punch” than waves that cross the current at an angle.
Other than waves, rivers create a fascinating display of textures visible as bubbles, swirls and boils. Each is a clue to changes in current speed and potential obstacles to be wary of. Look for water which appears rough and bumpy in texture, almost like gravel, and you most likely are witnessing an eddy line – the abrupt division between two currents. Knowing where eddy lines are is crucial for planning canoe placement to enter or exit an eddy pool and for timing your strokes for stable eddy turns.
The most common colour patterns on a river are long parallel bands of similarly shaded water. Each band indicates a speed of current with neighboring bands being either faster or slower. No set rule applies that one shade of water is quicker than another; you’ll have to be the judge as sometimes an eddy effect will be dark, while other times deep fast flowing currents will be dark. Suffice to say that it is the alternating dark and light bands which show changes in velocity.
By recognizing current speed, pick out the slow bands of water and determine if the currents are caused by submerged rocks that may have to be avoided if you select to run the rapid. If you’re planning to cross the river in a front ferry, adjusting your ferry angle to match the changing speed of the current will aid efficiency, and possible avoid an unfortunate loss of balance mid-stream when crossing from one current to another.
Reading whitewater is a lot like learning a language. The more you practice the better able you will be at quickly deciphering the message. Fluency comes once you can glance quickly at a set of rapids and “read” precisely where to paddle your canoe. Building upon the basic vocabulary of texture and colour will allow you to scout a safe route down your next rapid, or even more importantly, recognize when it would be safer to portage around it.