My PA is going to be stored on it's trailer I built last week (see an earlier thread I posted if you are interested in a PA trailer) and I needed to cover it to keep the weather and my cats off it. I'm not talented enough to really make my own, but I am pretty good at noticing when something can be made to work and saves me a little money. I saw this cover for a jon boat on Cabela's. Here's a photo and a link;
So basically all I did out of the box was unroll it on the kayak and attached the straps. Then I pulled the bungee draw string and cinched up the bottom so the cat can't get in. http://www.cabelas.com/product/Trailerable-Camo-Jon-Boat-Covers/751656.uts?Ntk=AllProducts&searchPath=%2Fcatalog%2Fsearch.cmd%3Fform_state%3DsearchForm%26N%3D0%26fsch%3Dtrue%26Ntk%3DAllProducts%26Ntt%3Djon%2Bboat%2Bcover%26x%3D0%26y%3D0%26WTz_l%3DHeader%253BSearch-All%2BProducts&Ntt=jon+boat+cover&WTz_l=Header%3BSearch-All+Products
The cover is on sale for $52.88. I don't think I could buy a cheap plastic tarp for that price.
The cover fits pretty well even though the kayak is 13' 8" long and the cover is for a 12' jon boat. I still have to trim the excess off the straps, but she looks good, sheds water and tight. The cover has several straps to tighten up and there's an elastic cord sewn into the seam all the way around.