Kami, a lot of good info and links in your post, and the idea of the vinyl in 40 gauge makes a lot of financial sense to me, specially from what the others have said. It's just for those few and far in between times when I just don't want to get wet. I take the boat out a lot on Biscayne Bay at night just to cruise, stop by the water front watering holes in the Miami River or the Intercoastal and I if the wind is blowing like tonight, east northeast winds 15 to 20 knots, I'm soaked to the bone while crossing the bay.
Thanks,
PS, About doing the job myself...not too sure about my skills in that area, but I'm going to see if I can buy the material and get a canvas shop to do it.