Plywood boat construction began in the United States about 1918 and developed rapidly; the two basic types are paneled and molded. Panel construction involves securing flat sheets of plywood to transverse frames and to the keel and other units that supply longitudinal strength; it is used only with chine-model boats, that is, those with flat bottoms or V-bottoms. The amount of compound curve that may be used in a plywood panel is extremely limited.
In molded-plywood construction the form of the boat is established by temporary transverse frames, or molds, and by longitudinal battens (thin, narrow strips of lumber often used to seal or reinforce joints), over which the planking is placed in two or three layers. The first skin is laid on diagonally and secured to the form by staples. Two or three skins are used, and after stapling, the mold is moved into a heating and pressure stage in which adhesion of the skins is accomplished. After adhesion, stiffeners and joinery are added; these usually include keelson, shoe, gunwale, guards, thwarts, decking, outside stem, transom (in a square-stern boat), and centerboard case and mast step (in a sailing hull).
Fishing in Newfoundland and Labrador
Plywood panel boats are flat-bottomed, a hull shape that lends itself well to fishing. Here, workers on a fishing boat haul a fish trap aboard off the coast of Cape Spear, the easternmost point in North America.