UV killed my last enclosure and I would like to do better this time. A clear view is nice, particularly in the winter when I don't lower the glass. I procrastinated a good long time, not seeing a simple way that didn't require a lot of holes, but I think I like this plan. If it makes it through the winter and proves to be as convenient (easy-on, easy-off) as I hope, we'll make one of Sunbrella in the Spring.
I added another tie in the lower center after taking the picture; that made it drum tight.
A simple tied strop at each of the upper corners is quick and requires no adjustment.
A strop can also be tied into a loop at the end of a line. Again, no adjustment required.
The tarp is a good 8 inches from the window. The trouble with typical snap-on covers is that they rub on the Strataglas, causing more damage than they prevent.
Three corners and the center front edge are attached with strops, so no adjustments are required. The forward port corner line goes forward around the toe rail and back to the midships cleat where it is easily tensioned. Very fast. Much faster than washing windows.
rev. 3-11-2013, 9-22-2016
Finally, after several years of testing, a more neatly tailored and more permanent Sunbrella version. Should last the life of the boat. about 9'6" x 37". with lap felled 2" hem on all sides (uses a standard width without trimming).