After listening to lots of good advice about my kayak that has a tendency to pull to port, I have tentatively decided to put what some are calling a "trim tab" on starboard side. I definately have a very modest curve at end of boat which I can see in the bottom chine and which I think is rejplicated on sides of panels. I will also experiment this weekend with some foam to build up side that curves away from center, so as to resymetrize boat as Paul suggested. If I like the result I may turn this into a more permanent fix with real materials. For the meantime, I will proabably go with the trim tab on the side.

This is my question. I suspect but do not know that water does not flow front to back under the hull of a kayak. If you just plop boat down into the water the displaced water would flow at a perpendicular angle to boats longitudinal axis - from midline to sides. I imagine that as speed increases the flow tends to straighten out but is never exactly front to back. The result of this for an off center fin that is under hull but not on midline would be that for any given speed there would be an angle of fin/skeg that would not apply corrective pressure because it would be in line with true direction of water flow. Conversely, a fin that ran parallel to boats direction of travel would have greater pressure on inboard side of fin and this would try and turn boat even though fin was straight. The least amount of drag would be at some angle to centerline, with the exact angle depending on the boats velocity. For best effect (least drag, most corrective action), I wonder if skeg should be angled for maximum performance at a specific speed (like 3 knots). On another list, I was also informed that current designs on sailboats and so on have an endplate at bottom of rudder or what have you to increase efficiency, presumably because this prevents water from "cheating" by sliding under rudder from the high pressure to the low pressure side. This simple idea adding a trim tab is getting complicated, although perhaps the impact of all these variables is negligible in reality.

Dave