Your first point is absolutely correct.
Posted by: g2d
on Feb-25-13 1:07 PM (EST)
But because I position myself up close to the center of the boat, the center thwart resists the inner pull of the strap. I didn't see visible distortion using the strap on my Bluewater (aluminum gunwales) though I'm sure there must have been some.
With my size 15 feet, I'll probably never try a kneeling thwart.
I tried an old foam pedestal on the Bluewater, the same one I "invented" in '73, and it worked pretty well. But I didn't keep it in the boat because it was shedding Ethafoam flecks from UV damage. I may make another.