The Roquayol-Denayrouze Aerophere

While many people conjure images of Jacques Cousteau and his iconic red cap when considering the beginnings of scuba, our story actually starts much earlier, in the 19th century.

The first true demand valve regulator was patented by Frenchman Manuel Théodore Guillaumet in 1838. A demand valve regulator allows a diver to take in air only as needed, rather than receiving a constant flow from a surface supply. Modern scuba utilizes this exact demand system. However, Guillaumet’s regulator was impractical at the time, and was largely overshadowed by more effective diving machines that relied on a continuous supply of air.

In the 1860s, French inventor Auguste Denayrouze submitted several patents for mining equipment intended to supply miners with air in an emergency. It relied on the same demand-style system that Guillaumet’s apparatus did. Though originally designed for use in mines, Denayrouze saw the potential in his creation for underwater use.

In 1864, Denayrouze collaborated with French Navy lieutenant and inventor Benoît Rouquayrol to create the Rouquayrol-Denayrouze “Aerophere”. This suit still utilized a surface supply of air, but relied on a back-mounted cylinder to supply air on-demand to the diver. This cylinder also acted as an emergency supply, and could be detached from the surface line for short periods of time, making it one of the first functional SCUBAs, or self-contained underwater breathing apparatus.