Peter, My M15 is under it's winter cover and that is covered with snow at the moment. As I recall, the hasp I bought (S/S) had mounting holes that were well below the edge of the sail locker lid opening. When you raise the sail locker lid, the inboard (cockpit) side has an indentation where the closed locker lid front edge fits. My mounting holes for the hinged hasp are below that edge, and presented no mounting problems. The other part, the square plate with the "U" was mounted on the locker lid. I don't recall if I had clearance problems, but if I did, I probably just cut off the bolt length, used a regular nut (thinner than an Elastic Stopnut) and put Loctite on it. The critical element is to have a slight interference fit of your hasp so that it won't just fall open by itself. Mine stays closed and requires a bit of effort to get it open. That way you won't have it opening inadvertantly if your leg brushes against it, or the boat gets hit by a powerboat wake. Connie ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/.