The envelope is a combination deck and bottom cover designed for long-distance trailering or storage. The cover is sewn together from the bow to the sidestays. From the sidestays aft, the cover is open. The deck flap features a reinforced hem and eyelets through which 1/4" line laces to hooks on the bottom cover flap to secure the cover. Three or four heavy-duty webbing tabs on the aft deck flap are used to tent the cover and keep it from pocketing water.