Jim,
The cover is attached with turnbuckles all around the bow and elastic lines at the stern (I will try to take some detail shots and post them). That was the original cover of the boat - 23 years old! It is some kind of fabric coated with pvc (or more likely some ancestor of that, given its age). I just had a new cover made, using the old one as the model. I have to take it up to the boat this weekend to mark the spots where the rings for the turnbuckles should be riveted onto the cover. The photo stinks - it is a scan from a contact print of a 35 mm negative. Couldn't find the full print. Will have to make another and then scan it.