I would state in your contract that you can not warranty any laminate over a plywood substrate.
Boats cabinets laminated playwood.
Tricel honeycomb panels are as strong as plywood for bulk heads cabinetry and furniture.
Plywood is an engineered wooden product manufactured by bonding wood veneers with each other using an adhesive and high temperature and pressure.
Plywood is normally sold in rectangular sheets of 4ft by 8ft 1220mm x 2440mm.
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.
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.
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.
If the plywood is required structurally then this becomes a messy problem indeed.
The main issue with using a non marine plywood is the eternal problem of time.
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.
The more veneers that are used the stronger and stiffer the plywood becomes so for bending fewer is better.