A few of us have made our own. Kits are available(SailNet) but Sunbrella is much cheaper on E-Bay. I bought a 10 yard roll recently, 60" wide, for $90. incl. shipping.
One feature I like is having it cover the mast to the deck. If your lines are at the mast like mine then they are covered along with the cleats and winches.
The link is to a friend''s boat. All DIY.