I apologize for the poor quality of my rendition of my suggestion. I envision my best attribute might be writing prescriptions.

Recognize, I have not put the track on the toe rail, but here are my thoughts, or lack of thought, regarding the project. I am not near the boat, and haven't looked closely at it recently prior to my comments.

The toe rail is an important structural component, in my opinion. The joint between the hull and the deck is perhaps the weakest part of the Ariel, and the joining surfaces of the two components must move together. The toe rail, for example, can not be allowed to lift relative to the hull, and the top of the hull can not be forced outward without a comparable forcing of the U shaped toe rail out.

As I recall it, the inside of the toe rail is quite irregular and rough.

My suggestion is that you use an aluminum 'U" shaped channel mounted inside the toe rail (You can get this material at ACE hardware). The track bolt goes through the toe rail, between the legs of the channel, and through the bottom of the channel. Underneath the channel, use a washer and nut.

The theory is that there will be no force against the sides of the toe rail or the hull causing them to flex independently. The nut will be mounted against a flat surface and the force holding the track down distributed across THE UPPER FLAT SURFACE OF THE TOE RAIL. If the toe rail curves inward where the legs of the channel meet it, the legs will be forced inward (an advantage of aluminum is that this forming is more easily accomplished) so that, again, there will be no force causing the toe rail to flex laterally.

If the inside of the toe rail is very round, as indicated by your drawing, an aluminum bar inserted inside the toe rail instead of the channel, with the bolts passing through the bar, could serve the same function. With the bar, you might want to place a 1/8" piede of neoprene between the bar and the inside of the toe rail. The purpose of the neoprene cushioning is to avoid point contacts. The neoprene distributes the forces uniformly across a broader area.

Anyway, that is how I would do it, absent a better idea. My concern with your proposal is the stressing of the deck/hull joint. Plus, I think it might be more complicated than necessary.

Peter