Techniques and tips for the big blow

BY JOHN WINTERS

I AM PARTIAL to heavy weather, possibly from watching too many reruns of Victory at Sea.

Sometimes I plow ahead at full speed, just to watch the bow rise and come crashing down into the largest waves. Childish perhaps? Sure, but it’s fun when time and destination aren’t pressing. But when they are, and you have to hunker down for a hard and sometimes scary paddle, the fun part fades. Knowing what to do can help when the going gets tough. Truly terrifying paddling calls for survival conditions, but that’s another topic. Now, onward into the waves.

Waves affect paddlers according to their length (distance from crest to crest) and their height (distance from trough to crest) relative to the length and speed of our boats.

When your speed is moderate and waves are long, the boat can follow the wave surface without additional resistance. But, when wavelength and boat length begin to coincide, things get serious. That’s when the boat refuses to follow the wave surface or cut cleanly through them. Instead, the boat rises over the crest of one wave and crashes into the next. The resulting spray, noise, and waves radiating away from the boat are energy lost. In the worst case, you can come to a complete halt.

The natural reaction is to use a bigger hammer and paddle harder, but it’s usually a mistake. There are three easier and more efficient methods to combat head seas. Two of them alter the period of encounter either by slowing down enough so the bow can rise and fall in time with the waves, or by changing course to hit the waves at an angle. Both increase the apparent wavelength and permit slow, but uniform, progress. Paddling harder will simply wear you out.

Meeting waves at an angle does have a drawback. Any angle to the headwind increases air drag and leeway. The net effect is to reduce your progress directly to windward – the worst possible angle is at 30 degrees to the wind.

A third method is to change the boat’s natural pitching period. When weight is spread out over the boat’s length (high moment of inertia) the natural period is long, which is advantageous in short, small waves. Conversely, when weight is concentrated near the middle (low moment of inertia) the boat will have a short natural period, which is better when waves are longer and pitching is more severe. Since small waves (relative to your canoe) pose few problems, it makes sense to load gear for the worst

case and keep weight out of the ends. There is nothing you can do about long overhanging ends that contribute to a high moment of inertia. Such are the costs of our aesthetic values.

An interesting thing happens when we paddle across really large waves. Because the local gravity is directed towards the wave centre, the boat follows the wave face, yet we get no impression of heeling unless the horizon is available as a reference. That hasn’t stopped so-called experts from conjuring up misleading illustrations of wide, flat boats tipping wildly while their roundbottomed cousins remain more upright. The best shape for large beam seas is one that will follow the face of the wave – wide and flat!

Nevertheless, most of the time we coastal and lake paddlers encounter much shorter waves. When the wavelength approaches the size of the

boat’s beam, the motion of a wide boat becomes more rapid. The steepest wave possible is seven times longer than its height. Problems can occur when a large wave breaks and the reduced local gravity and wind cause the wave top to detach and come crashing down the face in powerful disorder. Since roughly one-third of the wave breaks, the force is significant. Under these conditions, a boat with hard chines or a sharp turn of the bilge is at risk because it can “trip” over the chine and capsize as it’s pushed sideways by the cascading water.

Although it feels counter-intuitive at first, the remedy is to heel and brace into the wave – leaning away from the wave increases the risk of capsize. As a general rule, the best thing you can learn to prepare for breaking beam seas is a good instinctive brace. This is far more serious for open canoes than sea kayaks, so canoeists should learn evasive manoeuvres or wear spray covers in severe conditions.

Despite all the concern, I have never heard of a capsize caused by beam seas. There are many tales of capsizes due to attention lapses, being blown over by a wind gust, being swamped by a breaking wave, and from a boat slowly filling with water until it was completely unstable. But, I’m not aware of anyone capsizing due to waves alone.

Most of the time, following waves is just good fun with lots of spray and surfing, but it can get tense when they are steep and breaking. Fortunately, the seascape is composed of many waves of varying sizes, speeds and directions that constantly reinforce and diminish each other. Consequently, large waves disappear as rapidly as they appear.

The trick to handling following seas is to slow the boat by backpaddling a few strokes just as the wave crest is poised to hurl you down the face. Only in extreme conditions should you have to consider turning into the waves or resorting to drogues or trailing warps. Entire books have been written on that and they make great fireside reading. I haven’t had much luck with most of the ideas and rely more on braces and strokes.

One popular canoeing book describes how to escape from a wave that has you trapped on its face. Actually, staying on a wave is harder than getting off, and given time, the problem solves itself. The writer’s suggestion to try something that resembles a controlled broach is problematic and a sure invitation to go for a swim if the wave is breaking. Kayaks, of course, can turn and take seas on the beam and frequently do when surfing onto a beach landing.

Waves are one thing and wind is another. Most of the time, they appear as a package, but they affect your boat differently. Be prepared to adjust your style to suit one more than the other.

The way to combat head winds is to reduce your windage, or drag. Canoeists can use a spray cover to significantly reduce resistance. It also means getting rid of those wide brimmed hats and wildly flapping rain gear. I usually lose my hat in a few days which takes care of the first problem, and a lifejacket on the outside will tame the latter.

Paddling technique helps, too. Canoeists should feather the blade on the return stroke and kayakers can use shorter paddles with a twist. A more effective action is to control your angle with the wind. Remember, your net gain to windward will be least when the boat is at a 30 degree angle to the wind. So, if you are trying to move ahead dead to windward, do not angle to one side more than absolutely necessary to stop pounding.

Paddling into the wind is one of those times canoeists are allowed to consider setting aside their aesthetic principles in favour of “sit and switch” paddling. It isn’t pretty, but it is effective. Kayakers aren’t faced with this philosophical debate since they “sit and switch” and are aesthetically pure all the time.

The problems encountered across the wind are caused by sideways drift, or leeway. Drift moves the resultant resistance force off-centre at the bow to introduce a turning moment. Normally, this causes “weather helm,” which is the tendency to turn into the wind. The degree of weather helm is the complicated product of aerodynamic and hydrodynamic forces, with the latter by far the most prevalent.

Some boats simply cannot be made to track straight across the wind without extreme effort. I recall seeing a boat turn into the wind for no apparent reason. It took a minute or so before the paddlers got the beast under control and back on course. The owner’s lack of concern could mean it was a common occurrence.

While most boats turn into the wind, some will turn off the wind (lee helm). They are a curse to be avoided like the Ebola virus. The last thing you need is a boat that heads like a homing pigeon for the nearest rocky point downwind. The primary cure for any wind-induced course instability is either a rudder or paddling hard on the side that results in a straight course. Trimming the boat to adjust the helm works, but must be used sparingly because too much boat waving about in the breeze increases leeway. Using exaggerated control strokes (“J” strokes and such) slow the boat and the slower the boat, the more it drifts to leeward.

Should both paddlers paddle on the same side? You bet, if that gets the job done.

Enjoy! At least until the waves exceed your confidence level.

There is one more piece of advice. Wear your lifejacket when the going gets tough. Like most paddlers, I keep my jacket tucked neatly behind the seat 95 per cent of the time, but it’s that five per cent that will kill you. They aren’t fashionable or super comfortable, but they can make the difference between you being around for the next big blow, or not. ≈ John Winters is an experienced canoe designer living in Ontario.