@David R said:
Allan Olesen: Your statements confuse me the most, mostly because I don’t understand the terms “downwind” and “upwind” in this context. I don’t know what you mean when you say “the kayak pushed upwind”. I tend to categorize wind as “in my face” or some direction similar to that, or “coming across my boat” from one side of the other, or “a tailwind”. I suppose I’d better do some googling if these terms are important when discussing paddling.
Travelling upwind = Travelling against the direction the wind is coming from. (Wind in your face)
Travelling downwind = Travelling away from the direction the wind is coming from. (Tailwind)
Anyway, from this I get the feeling that you probably haven’t understood the purpose of the seat experiment. And you need to understand its purpose to get the intended benefit from it. So I will try to explain more thoroughly:
How a weathercock works
I assume you are familiar with the concept of a weathercock or weather vane. Otherwise look here or here.
A weathercock works like this: The weathercock is hinged slightly in front of the centre of the wind forces hitting it. So wind coming from the side will push the rear end more than it will push the front end. And consequently, the weathercock will always be turned around so it faces against the direction the wind is coming from.
If you wanted the weathercock to face away from the direction is coming from, you would hinge it more toward the rear.
And if you wanted the weathercock to be neutral to wind (which would defeat the purpose of having a weathercock), you would hinge it exactly at the centre of the wind forces. The closer the hinge point gets to the centre of the wind forces, the less the weathercock will be turned by the wind.
Thinking of a kayak as a weathercock
The above is exactly what happens with the kayak too (at least on flat water), with one exception: The kayak does not have a hinge. But the kayak is making sideways resistance in the water when wind coming from the side tries to push it, and the position of this resistance will decide the position of the “hinge point”:
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If the kayak makes a lot of sideways resistance at the front end and no water resistance at the rear end, it will behave as if it was hinged at the front end. And just like the weathercock, it will try to turn around so you face against the direction the wind is coming from.
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If the kayak makes a lot of sideways resistance at the rear end and no water resistance at the front end, it will behave as if it was hinged at the rear end and try to turn around so you face away from the direction the wind is coming from.
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If the kayak makes equal sideways resistance at the rear end and the front end, it will behave as if it was hinged at the centre, and it will be neutral to wind.
So when we are in a sea kayak and want to use the wind to our advantage, we want to “move the hinge point” so it suits the direction we want to travel in.
Using the skeg
One of the ways to move the hinge point is by deploying the skeg. When you paddle a kayak forward on flat water, with the wind coming from the side, a skeg equipped kayak will behave like this if the kayak is properly balanced for skeg use:
- If the skeg is up, the kayak will be hinged slightly toward the front. The faster you paddle forward, the more it will be hinged at the front. Consequently the kayak will try to turn around so you get the wind in your face.
- When you fully deploy the skeg, you create a lot of additional sideways water resistance at the rear end. So the hinge point moves far toward the back at the kayak. Consequently, the kayak will try to turn around so you get the wind in your back.
- With just the right amount of skeg, you balance your hinge point so it is at the centre of the wind forces, and your kayak will behave neutrally without trying to turn to either side.
This skeg adjustment is not something you just do once. The balance changes all the time during a trip, depending on speed and wind direction, and you have to adjust the skeg to compensate.
When the skeg isn’t enough, look at weight distribution
Sometimes you will find that the adjustment range of the skeg does not fit all situations. Perhaps your kayak will try to turn upwind even though your skeg is all the way down. Or it will try to turn downwind even though your skeg is all the way up.
In these situation you will need to look at your weight distribution in the kayak:
- If you have a lot of weight in the front, the front of the kayak will be deeper in the water, creating more sideways resistance at the front. So the hinge point will be toward the front.
- If you have a lot of weight in the rear, the rear of the kayak will be deeper in the water, creating more sideways resistance at the rear. So the hinge point will be toward the rear.
This was the purpose of the seat exercise. When you move the seat forward, you move your own weight forward, and the hinge point will move forward too, causing the kayak to go more up against the wind.
With this knowledge, you should read nickrowhurst’s suggestions again and try to understand what he wanted you to achieve with the experiment. And you will see that it crucial to the result that whenever the kayak is turning away from the direction you want it to travel in, you ask yourself this: “Is the kayak right now trying to turn up against the wind, or is it trying to turn away from the wind.”