I finally found some blue foam at a Lowes, but only in 1/2" thick sheets. I'll have to cut and laminate 5-6 pieces to make my airboat. That's good in one way as I can cut out the electronics and engine mount areas in some pieces before laminating and not have to dig out those areas as I would from a solid block of foam. I also plan on laminating in some pieces of 1/4" plywood to secure the engine mounts.

I've searched posts for info on glueing foam. I don't want to use gorilla glue as it expands a lot. I read posts where builders used white glue or 3M77 spray glue. Are either of these good for boat building. I have some Titebond II on hand that is highly water resistant. I also plan on painting the foam boat with latex paint when it'd finished. That should help waperproof the seams as well.

Any other suggestions?