Just a heads up, I purchased and applied the star-brite product listed above in late March as soon as could find a dry few days.
The product really appeared to work well as far as waterproofing. However I soon discovered the fabric was much softer after the treatment. Before is was fairly stiff, rolled/unrolled easily when taken off or putting back on the boat. Post treatment it soon became a limp noodle.
This week the cover ripped in two different places. Now the cover is toast. Apparently the sun reacted with the product and really accelerated the degradation of the fabric. Before the treatment I was expecting to get at least another full year of service from the cover.
Not sure what I will do next time, but I would not recommend this product.