What counts as an early inflatable
A boat held up by air rather than by a rigid hull is a surprisingly old idea. Inflated animal skins were used for crossing rivers in several ancient cultures, and historians often mention skin floats in descriptions of ancient warfare. These, however, were closer to rafts or flotation aids than to the boats described here. The craft covered in this article are the manufactured inflatable boats made of rubber and fabric, which only became practical once rubber could be treated to survive heat, cold and use.
Rubber becomes usable
Natural rubber had been known in Europe for some time, but raw rubber became sticky in warm weather and brittle in the cold. The processes later called vulcanisation, developed in the late 1830s and early 1840s by Charles Goodyear in the United States and Thomas Hancock in Britain, made rubber far more stable. Rubber-coated cloth then became commercially available for waterproof clothing, tents and, before long, boats.
Mid-nineteenth-century inventors tried various rubber-and-canvas designs. A well-known British example is the Halkett boat, devised by Lieutenant Peter Halkett of the Royal Navy in the 1840s. It was a rubberised cloth craft that could be worn folded as a kind of cloak and then inflated and paddled across water. It was a small and delicate boat, but it was reportedly taken on Arctic journeys, and it shows how explorers valued something that packed small and weighed little. This was a useful trait in polar sea exploration, where carrying a rigid boat over land was impractical.
Military pontoons
Armies were an obvious market. Floating supports for temporary bridges were a long-standing need, and inflatable pontoons offered a way to carry bridging equipment in compact form. Rubber pontoons were reportedly tried by several armies in the mid-nineteenth century, though wooden and later metal pontoons remained standard for many years. Military engineers continued to experiment with rubber and fabric supports for pontoon bridges and assault crossings, and by the First World War inflatable and folding boats were among the many specialised craft in use. Details of individual designs from this period are patchy, and it is safest to say that they were present but not widespread.
Aircraft and life-saving rafts
The growth of aviation created a new need. Aircraft flying over water needed something that could be stowed in a small space and inflated after a crash. Between the wars, and especially during the Second World War, inflatable dinghies and rafts became standard equipment for many bomber and maritime patrol crews and for naval vessels. Some were circular or oval, others had a more boat-like shape, with a canopy or a small sea anchor.
The numbers of airmen and sailors who relied on them is difficult to state precisely, but survivors of attacks in the Atlantic convoy battle and other campaigns often drifted in rubber rafts and dinghies for days. Their role was survival rather than transport, and they were generally ill suited to sailing or to rough passage-making.
Wartime assault craft
The Second World War also brought more purposeful boats. Allied forces used inflatable assault boats for river crossings, raids and landings from submarines and larger ships. Small rubber boats let reconnaissance parties and commandos go ashore quietly, and they could be paddled or fitted with a small outboard motor. Folding canoes were used for similar tasks, and the two were often seen as alternatives. Inflatable boats were more stable and carried more, but they were slower and more exposed to wind.
Developments in synthetic rubber during this period mattered. Neoprene, a synthetic rubber first produced commercially in the 1930s, resisted oil, sunlight and abrasion better than natural rubber. Later materials such as chlorosulfonated polyethylene, sold under the brand name Hypalon, and then PVC-coated fabrics improved durability further and allowed manufacturers to bond seams more reliably.
Peacetime manufacture
By the late 1930s and into the postwar years, several companies were making inflatable boats for civilian customers as well as for the military. Surplus wartime boats found their way into civilian use, and manufacturers in France, Britain, the United States and elsewhere turned to leisure, fishing, diving and rescue markets. The French firm Zodiac, which had earlier been associated with balloons and airships, became one of the best-known names, and its boats were widely used in diving and expedition work.
The next steps, including the inflatable tender carried by yachts and the sail-equipped inflatables of the 1950s, are covered separately. So is the rigid-hulled variant that combined a solid bottom with inflated sides, which became important in rescue and military roles from the 1960s.
What the early inflatables show
The history of the early inflatable boat is mostly one of materials. The shape of a simple inflated boat was settled quite early, with tubes round the edge and a flexible floor, but its usefulness depended on the quality of rubber and the glues that sealed it. Each improvement in synthetic rubbers and fabrics made inflatables lighter, more puncture-resistant and longer-lasting, and widened the range of uses from expedition equipment to life-saving gear.