Hi IslandHopper, welcome Aboard. Unfortunately, you are replying to a post submitted on 06/27/08 (just shy of 4 years ago). Unfortunately, the original poster (OP) has only submitted 2 posts (One of which was 4 years ago). I believe that a boarding ladder is a required piece of safety equipment, though that may vary from state to state. If it is not a required piece of safety equipment, then it should be. You NEED a means to get a person back on board should they fall overboard. Even docks are required to have a ladder in the event someone falls in.
Sealing the cover closed would be a very bad idea IMHO. We are talking only about the cover, correct? Do you NEED the cover? A few pics of the problem might go a long way towards a solution. If yo ucan upload a few pics or a detailed description of the cover failure, then it might make it easier to suggest a solution. I would be very surprised if this was afixed to teh boat with a adhesive sealant from the factory. These things are easy to break if kicked by someone while it is up. I would suspect the previous owner (PO) probably broke it and you are looking at how he fixed it. Just my .02