RE: Adding chocks for tender to sun deck top
Phil Fill - good idea on the surveyor method, and the stud finders. Non invasive.
Old Stone - the top is about 3.5 to 4 inches thick. 5200 is great stuff, but bolts and 5200 would be less worrisome in a seaway. Definitely plan to goop up any holes liberally. Would like to find the ribs so that I do not have to trough bolt.
Larry, great pics! If I get in and find I missed a joist or there are none, I'll plan on through bolting w/o the big backing plate, just washers - very cool.
Coast Guard Dave - nice idea. We don't really use this deck for anything else...haven't had the chance yet, but will post pics of the boat.
These are all good ideas and every one helpful. Thanks!! I'll try to let everyone know how it turns out.