Hi Shaggy
There are a lot of ways to construct a wooden hull, but if it is only coated with paint it is really susceptible to all kinds of damage and deterioration.
Therefore the hull is sheathed in fibreglass.
There are all sorts of exotic sheathing materials and techniques nowadays.
But the older jobs didn't have access to those materials and as Ramona suggested could be hiding a nightmare. Here is a vid of little simple strip planked boat that is sheathed and faired.
Gary