Thunderbirds are wood.
Thunderbirds are built in both wood and fibreglass. Plywood is a pain. M ore second hand Thunderbirds would probably be purchased if there were more used fibreglass Thunderbirds on the market. The Thunderbird embodies family sailing. Its origins are in a competition sponsored by the Douglas Fir Plywood Manufacturer's Association in the late fifties, to design a quick, stable boat that could be built in plywood and would accommodate four.