Building a FRG Boat.
Perhaps it is not a rational thing to do, but
If you take pride and pleasure in building a boat...go ahead and make YOUR boat.... pleasure is not a rational thing.
I would stay out of fiberglass and would prefer Marine Plywood and Epoxy. It fells and smells a lot better and you don''t need a mold.
Epoxy can give very low care and good durability to plywood.