This year my lovely wife built a winter cover for IDUNA. The zippered three panel cover is made from 6.5 oz Odyssey II cloth - similar to sail cloth. IDUNA's boom and downwind pole were used as ridge poles. The cover keeps 98 plus% of the snow off the boat. All the zippers are covered and where a zipper or common sense fastening passes over the boom or bulwark , a small protection panel prevents the zipper or fastening from scratching the paint. The cover is built just similar to the BCC - "Stout Tough."
P.S. After my efforts to help Lenora by sewing a seam, I was kindly asked not to touch her work after she unpicked about 12 ft of stetching. The windvane is a Cape Horn.