hi dave,

> Does anyone know the propper size for a skeg?

I had the same question few months ago. I went to the kayak dealer & measured existing boats with skegs. the average skeg size was approximately the same surface as the palm of my hand when it's fully extended. I asked a friend of mine, student for aerospace engineering & he told me in these speeds the shape doesn't really matter, just make the diagonal edge face forward.

> Also I've seen many
> kayaks with the skeg mounted well forward of the stern to the point that
> it interfears with the storage space. What is the advantage of this
> arangement over placing the skeg as far aft as it will fit?

at the rear tip of the stern the skeg will have the strongest effect as far as improving the tracking. the problem is it will be out of the water with even small waves, & it will make paddling harder. that's the reason they move it forward. the lost of tracking effect exists but it's minimal. the kayaks dealer told me a rule of the thumb: stick the stern into your shoulder, as if you're holding a gun, extend your hand along the bottom center of the hull (keel ?), then place the trailing edge of the skeg at the edge of your finger tips (or so). it's a rule of thumb, so I believe it's true for 16~18 feet kayaks.

another issue with skegs is the center of pressure. when the skeg is extended it moves the center of side hydrodynamic pressure in relation to the side aerodynamic pressure. in plain english it means you'll be able to steer into or out of a side wind by controlling the portion of the skeg's surface that's extended. I read somewhere a testimonial of somebody that's doing it. regarding this issue, you want the skeg to be located in the exact point where it's steering effect will be the maximum, & not it's tracking effect. I'm sure you don't have any idea where that point is.

I plan to install a skeg on my coho, but did nothing about it yet. everything I said here is theory.

hope this helps.

erez