Haystack
Best luck I've had with tarps for my Cat-22 is one of the large heavy duty silver colored tarps made to cover haystacks. You can buy one oversize and cut it down to fit, probably in your case making a slit from the front to get around the mast, then overlap forward when you tie it down. Small stones tucked into the tarp can be tied around with double half hitches, or you can install grommets to tie whereever you want. Biggest problem, is the cockpit area where it needs some support to keep from sagging when rain and ice form. In my case and probably yours too, successive snow forms and melts, and then freezes into very heavy blocks. Or you can purchase a much more expensive cover custom made for C-22's. Dick