I bought some sunbrella material off of eprey along with some brass grommets and two plastic zippers. After taking a few measurements, I had my wife use her home sewing machine to make a two piece cover with the break at the center beam, that just drapes over the hulls. The Sunbrella does last a lot longer than the blue tarps and handles the wind much better as well.
Harbor Freight sells hole punches that you chuck up in your drill motor. I used them and a plastic cutting board to create the holes for the brass grommets. Don't forget to put grommets in the middle of your tarp for drainage.
I also have a cutom made cover, and must agree is a PITA to put on and take off.
If you can't sew, but know how to use a measuring tape and scissors, you could run a bead om 3M 5200 around the edge, fold the edge over and clamp between a couple of 1 x 2"s. This might be hard to do near the zipppers that you will need to install around the shroud lines. A little hand stitching may be in order there, and you could use velcro, if you planned it right.