How well a blue tarp will work as a cover, depends on where you live and where you store your boat. I live in Houston. In my back yard, a blue tarp will last about a year. In the boatyard, it will last about 2-3 months in the summer. The boatyard has no shade and is the middle of the largest concentration of petrochem plants in the world.

Don't go by the color of a coated polypropylene tarp. Look at the thickness or the weight. The thinness I remember was 2.3 mil and the thickest was a 15 mil white one from Australia(it lasted almost 2 years). I messed up last year, I grabbed a silver/back tarp on sale. I was halfway through making a cover when I checked the package and found it was only 4 mils. That cover lasted until July.

This year I am trying something different. When my my cover feel apart last year, I whined and complained finally said "those yellow Naugahyde rudder covers and storage bags are 25 years old and have been in direct sun for at least 15 years".

The yellow Naugahyde cover for the A-Class has been working great for the last month. The rest of the material came in Tuesday, so I will start on the Wave cover and a mast cover for the A.

I will let you know how Naugahyde works. The bottom is open so I shouldn't have any condensation issues. It's waterproof and with the cover fitted to slip over the bows and sterns, it only needs 4 ties. It's just too heavy to move.