Using mechanical fasteners is also a good idea with polyurethane glues but in some cases is not needed. As always I refer new builder to the actual designer of the boat. Hi Don, by reading their statements. Hi Les, and how do you interpret what they are saying. The link below will take you to the 3M Australia Marine site.
Polyurethane adhesives are certainly simpler.
Also another site with 5200 information. Let me tell you a story. This was a fiberglass boat. All rights reserved.