Re: Jerry can & fender covers material?
Second the Boat Blanket choice for fender covers. Tough but soft on your gel coat. Sunbrella would be too abrasive for fender covers.
Boat Blanket material is sort of like the fuzzy half of velcro and will stick to the hook side of velcro. you sew a strip of the hook on the edge of the blanket material and it will velcro to itself when you wrap it around the fender. Working well for us for 3 years so far
As for dark jerry cans, we have issues with heat build up causing overflow on the red jugs. Our covers are oyster sunbrella and that works to keep them cool in the sun. However we're getting black spots on the sunbrella, maybe bits of mold? in the sun? Not sure, but they do work as covers. Will be addressing the spots soon...