gps test it is then
Okay, based on the responses in the second half of your post and more ruminating on my part, I’m starting to believe that perhaps you could test the effect without forward motion. I’ll do some experimenting this summer, but I’m not sure if my Wildfire is the best choice of boat for it – a wider boat should have a much more pronounced effect, I would think. Plus, I’m still a novice at the Canadian style thing, but I’d welcome an excuse to work on that anyway.
MMC would be a better choice, both for the boat and for the paddler. MMC, are you still around? If so, please take this as a challenge to prove your sailing claim – see the two paragraphs at the bottom of this post.
On the first part, I think I may be correct there, let me see if I can explain this part with my limited knowledge in a way that convinces you. Let’s start with sailboats, which we both agree can sail somewhat into the wind. The Bernoulli principle, which as you say provides lift to shaped wings, also provides the thrust for a sailboat aimed into the wind. The principle says that when air passes around an object shaped so that the air must travel further on one side than the other, there results a force in the direction of the side with the longer path. On a wing, the bottom is flat while the top is curved – the curve is the longer path – thus the force is up. On a sail, the outside is curved, while the inside permits the air to rush straight across, so there is a force toward the curved side of the sail.
However, when you push a sailboat toward the curved side of the sail and the boat starts to lean over, the keel offers you some resistance and thereby converts some of the sideways push into forward motion. Thus, the “lift” or push force on the sail resolves itself into two vectors, one pushing the boat to lean over and the other pushing the boat to move forward. (I get lost here in my vector math, but perhaps you can take it from here. If you resolve these two vectors into a single force, that should be the force you expected, but I’m not sure if it is at a right angle to the wind or in the same direction, or possibly in relation to the sail instead of the wind.)
Anywho, however the science part goes, I think we agree now that a GPS test could answer the question. What exactly should the rules for the test be? I propose a lake with an area that is subject to a steady wind in a steady direction (having a wind meter would be superb so we could measure the wind’s velocity, but we can do without). The paddler can set up at any orientation to the wind he wishes, and then he will take a GPS reading and a wind direction reading. On a hypothetical map, we will plot the position and draw a line through it in the wind’s direction. If the ending position is anywhere forward of that line, it indicates forward progress. If it is anywhere along the line downwind from the initial plot, it indicates no forward progress. (Any other position indicates an error occurred.)
Once in place, the paddler can use his paddle to hold his chosen bearing to the wind but should avoid a preponderance of forward or backward strokes, and he should keep his paddle in the water and held firm as much as possible as well as sitting or kneeling in a stationary position, since his paddle will be acting as a partial keel and part of the sail force (if any exists) will be passing through his body to the boat.
Exactly!
Canadian style was created to answer the question “how does a small solo paddler control a big tandem boat?”
It is not the only style, and is unsuitable for whitewater, flatwater racing, or certain dedicated solo boats.
We used to paddle with a real tiny guy
who ran whitewater in an Old Town Tripper. He was very good if the wind wasn’t up. I think his style could be called, “Frantic Lilliputian.”
One Question, One Clarification
The Question
What does this mean? "On a hypothetical map, we will plot the position and draw a line through it in the wind’s direction. If the ending position is anywhere forward of that line, it indicates forward progress."
Are you saying the line should be drawn in a direction that is 90 degrees to the wind? That would make sense, as if you can end up on the upwind side of that line, you have made progress against the wind. However, if you are saying to draw the line in-line with the wind, that won't show you anything, because any crosswind componant to your drift will push you across that line, and any boat positioned at any angle to the wind will move crosswise to some extent as it drifts downwind. What you want to prove is that in addition to the crosswind componant you can also move upwind, so "forward progress" in this case must be defined as some degree of travel against the wind.
So, what you need to do is draw the line cross-wise to the wind and see if you can sail your boat to the upwind side. I promise it won't happen (see below) but everyone is welcome to try.
Clarification
I agree completely that a sail can produce lift. The problem is, lift comes at a price, and that price is wind resistance (that's the reason airplanes need engines and it's the principle behind why the theoretical perpetual-motion machine in my last post won't work). Wind resistance can only act in one direction, and that is in the direction that the wind is pushing. THAT is why the axis of the sail and the axis of the boat can NEVER be in the same plane, but clearly describing why that is so would take too long right now (maybe I'll shoot you an email later on). The axis of the sail MUST be oriented at a smaller angle away from the wind direction than the axis of the hull to make the net force on the hull act in some direction other than straight downwind. If you only have a downwind force, you can still steer a course that goes somewhat cross-wise to the wind by adjusting the boat's angle and utilizing the boat's "grip" on the water, but the direction of drift will always be partly downwind (or more accurately, "mostly" downwind). To use wind power to go 90 degrees to the wind or in ANY direction that is upwind of 90 degress to the wind, the sail and boat hull cannot be at the same orientation, and thus the sail and hull cannot be one and the same object (ignoring all the imperfections of "real life" (failure of the hull to properly grip the water, for the most part), you could sail in a direction that is only 1 degree in the downwind direction with a sail that's perfectly lined-up with the axis of the hull, but in real life you'd never even get close to such a crosswind heading before encountering the need to align the sail at a shallower angle than that of the boat). Again, anyone following this thread can certainly try it.
**************************
Okay, I thought of something else. In case my other examples don't explain why you can't use lift to move against the wind, here's a perfect example. There are kites which work just like sails. Imagine flying a kite, and trying to fly it higher and higher by steering it closer and closer to a position straight above your head. It can't be done. Obviously you can't fly the kite straight up overhead and then to a point upwind of you, which is what you could do if the force of lift could be directed in even the slightest bit of an upwind direction. The string of the kite must always resist the force of the wind to make the kite generate lift, and thus that string will always be in tension and will always be oriented at less than 90 degrees to the direction of air flow. Going back to the sail on a boat, this AGAIN relates to the reason the sail and boat cannot be one and the same, but must have orientations that are different from each other (but I'm afraid THIS aspect isn't made any clearer by my latest example, so anyone who didn't get it before won't this time either).
Sailing
The sailing effect is real. I have felt it many times and take advantage of it if the opportunity arises (especially on lakes). In trying to understand it, I too have looked for the possibility of a Bernoulli effect but have not found it. I prefer a resolution of forces approach. The wind hits the windward side of the boat (heeled side) and energy is transferred to the boat. As the rear of the boat is in water as there is weight towards that end (me), little motion is possible in that direction and energy resulting from the wind is transferred to the water. The same for the lee side (paddling side). The remaining energy, If there is any, can only go in the direction of the front of the boat. As there is little resistance from water at that end, the boat is propelled forward.
A couple of points. The canoe has to be continuously paddled for the wind effect to be experienced. This suggests a Bernoulli effect contradicting what I said earlier. The alternative is that the forward effect is small and not sufficient to maintain any forward momentum without paddling . Another point is that the size of the wind effect depends on the angle of tacking. For example, if travel is perpendicular to the wind or too close to the wind, there is no effect. An angle somewhere between these two is where one wants to be. Finding it is not hard.
Bernoulli Effect
Would you say this Bernoulli effect deals with wind or water passing over the hull. If it's the wind, the need to paddle forward isn't part of the deal. I know exactly the "feel" of the boat that you are talking about, but I maintain it's an illusion. I've discussed other paddling illusions here before, mostly having to do with the effect of current. I believe this is similar, as all my GPS experiements tell me that nothing "real" is happening in spite of what it feels like. I really think the sideslipping of the boat in the wind creates the sensation of extra speed because water IS slapping the boat harder, and adding a sideways componant DOES increase your velocity, but the componant of that velocity in the the direction you wish to go is not enhanced.
If you are talking about a Bernoulli effect due to water passing over the hull, I think that's really nothing more than one componant of the resistance your boat provides against sideways motion. I envision that process as either "lift" or a simple "ramping" action (or both) that will help resist your downwind drift, but since it is totally reliant upon your own power, it's not harnessing the power of the wind but fighting it. In other words, if the wind were not trying to push you sideways, the lift or ramping effect of your hull passing diagonally through the water would be eliminated and your boat would move straight through the water instead of slipping, causing the upwind componant of your velocity to increase (just another way of showing that you are fighting the wind, not using it). That's the difference. Still, I really do know the "feeling" that you describe, but whenever you are dealing with more than one force upon your boat, isolating what is really happening gets tricky.
Funny how Bill Mason used it
(Canadian style)pretty successfully to negotiate some whitewater.
His books have tons of pix..
Heel does not have to be radical..but note how he drops back a little and is not at the pivot point.
Line picking may be key...certainly his boats were not playboats.
It would not be my personal choice for whiteater though.
e-mailed ya
e-mailed ya
Canadian style
I just want to add a word or two to counter some of the misconceptions of Canadian Style. The degree of leaning (heeling) of the canoe is flexible and determined by knee position in the canoe. Sitting close to the gunwales is great for turning and paddling straight. In windy weather moving the inner knee closer to the centre-line, flattens the canoe and reduces exposure to the wind resulting in better control. This approach is also used for whitewater.
And yes I am promoting Canadian style because fewer paddlers are embracing it. The result is that many elegant and sexy strokes, a few of which I mentioned earlier, are not be known by paddlers today and maybe be lost. A pity! Can you do a 360 degree turn on a dime? I can.
Yes.
often more… and slicing draws and pries while pivoting…well sometimes I get really dizzy.
you are correct in that heel is adjustable.
The lack of CS popularity seems to be due to peoples seats being more developed than their knees.
360+ double-bladed
With a double-bladed paddle, I can do 360 after 360 after 360, probably with much less effort than you (dip left, small stroke back, dip right, small stroke forward, repeat), and then come out if in a burst of speed in a chosen direction when the signal comes.
I actually do this sometimes and it’s not for show but for a purpose. I’ll set yo-yos around the edges of a lake cove or in the bend of a river, then take a central position where I can see all of them. When the fish are biting good I actually do start doing circles, and as soon as I see or hear a fish take the bait, I run off in that direction.
I’m not trying to challenge CS style in general. I’m sure an experienced CS-er can do many things I can’t either double-bladed or single, but when I read that you chose circles to boast about, I just had to speak up. Circles are a natural for a double blade.
And you thought they were only for going straight!
j/k