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Sea Kayaks Techniques Bulletin Board
Re: Surfing Question...
Posted By: Jay Doorly In Response To: Surfing Question... (Petewp)
Date: Tuesday, 20 July 2004, at 12:10 a.m.
: Ive seen it mentioned a few times that some folk like to surf diagonally
: across the wave [chop?] face - Im guessing to lessen the burying of the
: bow.
: I paddle [ahem - "surf"] waves no larger than 2' max, does this
: apply with these size? Because my yak tracks so very strongly, I find Im
: hopelessly doing sweep strokes to avoid a broach and always always losing
: speed as a result. Proof in the pudding is that my flatwater cruising
: often has higher peak speeds than my following sea "surfing" due
: to constant sweeping - and stern rudder when it gets out of hand - the
: most costly action of them all.: Would diagonal paddling help hear - frankly I only see it inviting a faster
: broach - still for other people it seems to work - any opinions?: Pete
A confusing thing kayak surfing. What seems to work one day doesn't work the next day. Hard to gather empirical data, I'm definately missing some important force in my unified theory of "look ma no paddle!". Certainly angle to the wave has an affect but the optimal angle seems to vary with conditions. Boat velocity and accelleration, wind velocity and direction, wave height, tide or currents, edging/leaning, ...
I think the first thing you have to understand is that the wave train has micro currents. Looking at a wave from the side you see a classic sinusoidal wave form- a peak, a trough, and a peak. Under each of these is a circle (actually a cylinder) of current. The current under the peaks is moving with the wind (near the surface) and the current in the trough is moving in the opposite direction (near the surface). A good metaphor would be three gears each meshing with the adjacent gear, so the first gear represents a wave peak current as it turns, lets say clockwise, the second revolves in a counter-clockwise current, and the last moves as the first, ad infinitum.
So, your kayak has these forces pushing on it, some propelling. some retarding. A normal size kayak when spanning wavepeak to wavepeak will be somewhat lifted out of the trough and thereby minimizing retarding forces. As the angle to the wave moves away from perpindicular this minimizing of the evil trough forces increases until the length of the boat is not adequate to span the peaks and the boat begins to settle into the trough and slow down. Now, as the boat continues to settle into the trough the evil trough forces overpower the good peak forces and the paddler must lean into the wave so as not to capsize in a broach.
These same currents are moving around in your bow wave, trough, and stern wave, and they are interacting with the weather waves, and synergy in occuring when your boat is perpindicular to the wave. The complementary currents and waveforms add together at the peaks and add negatively at the trough further lifting the boat away from the evil trough forces. Yaaay, hooray for our side!
When racing a sailboat to windward an able helmsman will scallup and feather a coarse thru waves which may maximize trough time, if other conditions merit it.
The vast majority of the time I paddle harder and try to catch a wave at some angle I subjectively think is best. I can feel an accelleration and I get some push from the wave but I have to keep paddling. To me this is only a push, it is not surfing. Surfing is when you stop paddling and use the paddle as a source of resistance in order to steer. It is often associated with heavy excretions of adrenilen, newfound respect for the forces of nature, and a humbling sense of frailty and good fortune. Cowabunga!
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