The late 1940s, following World War II, were a time of economic retrenchment, but as the US and international economies boomed in the 1950s the pent-up technology within the boating industry exploded with innovation and production. World War II was the catalyst for development of compact engine systems, mass production of plywood water craft, and advances in hydrodynamic design. Another outgrowth of war production was fiberglass; the first fiberglass boats were made in the 1930s but practical production did not begin until the 1950s and then more as a supplement to wood and plywood than as a structural component.