On my boat the original plywood was glassed on top, and naked below.
My replacement will be plywood glassed on all sides.
The original lasted 20 years, if the replacement lasts at least that long it will not be my problem!
Interestingly, there were three Amel SM in the yard here in the last month. Bow locker reflooring was on the agenda for all of us...
Fort Lauderdale, FL