What composite alternatives to marine plywood can I use to replace a structural bulkhead in a sailboat?

Answer 1

You can also use a foam core. This is very popular in the boatbuilding industry. Divinycell is the largest manufacturer. It also has the advantage of being very easy to cut and shape.

Of course it needs to be incased in fiberglass. Divinycell makes sandwich panels (glass-foam-glass) to make this easier.

Answer 2

a honeycomb ( Nomex) with glass on each side or balsa core with glass.......although if the boat has been engineered and the interior fitted around marine ply, why re-invent the wheel....just make sure to seal the endgrain well and truly with epoxy before installing