I bought one of these when I got my raft six years ago. It started have some issues a couple of years into use. http://www.whitewaterdesigns.com/ho...lated_raft_storagetravel_cover13_14_wtie.html
It completely fell apart this year. For the money I had had hoped it would have lasted longer.
I went to WalMart and bought a car cover for $45.00.
Home Depot and Lowes sell tarp clips. I attached carabiners to the clips, then clipped those to the trailer handles.
It fits like a glove and so far so good. If it only last two or three years, I'll just go get another one.
Marine/boating canvas shops will take measurements off your raft and create a custom fit cover from Sunbrella fabric, or something similar. I don't know where you live, but shop around and you'll find plenty of them in the greater Puget Sound area that would be happy to have a customer, I would think.
...or, just do what Stonefish did for a less expensive option.
Either way, your boat will be a lot happier and live a longer life if kept out of the sun and weather if kept with a cover over it.
So much cheaper and you can sinch if needed.
Plus they are made for uv protecting lighter and roll up smaller.
Also dry faster.
110 $ for top of line compared to 325 $ boat or custom cover.
There are better more useful tools you will need save yoyr money for that.