[rheavn]

Using adhesives are the best from an appearance standpoint. You could just glue it on or use double sided tape. Since you park on the ocean I would want a complete seal, so as not to allow salt air getting to the metal below. Other alternatives that won't be as attractive is to pop rivet or use self tapping screws. I would think with this method you would want to caulk the edges to again avoid salt air intrusion. I'm sure others will have other ideas.