A wood core, either strip, tortured ply, and a crash bulkhead would work very well. A nice side effect is that the fairing of the hull results in wood shavings and wood dust, not plastic dust. Some commercial builders still use this method (Steve Rander of Schooner Creek Boatworks is one) https://www.schoonercreek.com/custom-boat-building-past-projecti want my hull be light and able to get me from point a to point b fast, also having a chance of not penetrating the hull by a stray container, its fine if the outer layer will be penetrated, but you know...it would be nice to be able to get to the harbor without ditching a boat.
The West book on wood-epoxy boatbuilding will tell you everything you need to know about this method.
I made a small catamaran for my kids using this method - strip plank bottom using bead/cove strips ala building a kayak, and ply topsides and deck, coated in glass. It's a Dudley dix design, and he has a few cruising boats using similar methods of construction. https://www.dixdesign.com/designs.htm
Nice thing about using a design of his is you can have a local mill CNC out your jig frames.