When a laminate sheet is glued to its surface it becomes a laminated plywood the laminate sheet serves both decorative and protective functions for the plywood.
Boats cabinets laminated playwood.
At fisheries supply we carry a variety of marine construction boards from trusted brands like coosa composites king starboard taco and more so shop now for all your boat.
Mdf is the way to go.
Given sufficient time and use it may be that the protective fibreglass layer becomes damaged allowing water to permeate the surface and begin to rot the underlying plywood.
I would state in your contract that you can not warranty any laminate over a plywood substrate.
Plywood is an engineered wooden product manufactured by bonding wood veneers with each other using an adhesive and high temperature and pressure.
If the plywood is required structurally then this becomes a messy problem indeed.
Plywood is used for a plethora of interior exterior and structural applications.
But tricel honeycomb panels can weigh up to 80 less than plywood which means you can design and build the luxury customers expect while giving them the economic benefits and operating performance they demand.
Plywood is normally sold in rectangular sheets of 4ft by 8ft 1220mm x 2440mm.
The main issue with using a non marine plywood is the eternal problem of time.
If it calls for it in the plans ask the builder to call the architect or customer to see about changing it to mdf.
Tricel honeycomb panels are as strong as plywood for bulk heads cabinetry and furniture.