2 part polyurethane foam as adhesive to blue foam

Gonzo,
I guess I should have been a bit more clear about my thoughts on this.
Like the blown in foam that I pulled out, I want to fill the entire space from the inner surface of the hull up to the bottom inner surface of the deck, between all of the stringers and structural crossmembers ; the entire inner cavity under the deck ( except for a space for accesss to the lower engine bolts through the transom ).

 

Every boat I've ever seen that was filled up with foam was full of mildew, condensation and just a mess. If you really insist on flotation why not use some type of inflatable bladder? I realize we're all different. I eliminated all of the foam That I found when I restored my boat. I installed two good bilge pumps and an attachment for my seacock that allows my main engine to act as a bilge pump in the event I have an emergency and am taking on very large amounts of water. But, aside from testing my pumps never run. I have a dry bilge, as in you can throw a paper towel down there today and it will be dry tomorrow. Packless shaft seals, installed properly and well sealed hull to deck joints, etc. make this possible today. Having decent air circulation under your cabin sole and in the spaces between stringers and floors really helps your boat fight condensation and be mildew free and smelling fresh. You know, not smelling like most boats. Consider keeping the water out to begin with and having the ability of getting it out of the boat should you somehow have a hull breach.