This was the first sailing boat to be mass produced and was generally built in batches of two or three dozen boats. Hull construction was of three layers of 1⁄8in (3mm) spruce that had been stockpiled for the war effort, changing to 2.5mm agba veneer when this became unavailable. The planks were applied over a male mould with each temporarily held in place with staples.
Once planked up the boats were put in a vacuum bag and heated under pressure in an autoclave for 30 minutes. This process compressed the planks together, activated the glue and helped it impregnate into the timber. The result was a lightweight yet stiff monocoque structure that could be built in around half the time of a traditionally planked clinker dinghy. It sold for just £65, including an aluminium mast. When the boat was selected for the 1948 Olympics, in which legendary Danish sailor Paul Elvström won his first of his four gold medals, the Firefly quickly gained recognition and popularity.
Hot-moulded construction was quickly rolled out to a wider range of craft, including the 15ft Albacore, the 18ft Jollyboat dinghy and the Olympic Flying Dutchman class. It was also used for larger boats, including the 26ft and 31ft Fairey Atalantas.