In June 1943, the overnight express train from Paris delivered a large wooden crate to the station at the Mediterranean port of Bandol. The crate was addressed to a young French naval officer by the name of Jacques Cousteau, who later wrote: "No children ever opened a Christmas present with more excitement than we did when we unpacked the first 'aqualung'."
Within hours, Cousteau and several friends were in the water testing the device, which they suspected would revolutionise diving. Using technology invented to allow cars to run off gas during the Second World War (designed by an engineer named Emil Gagnan), Cousteau's patented aqualung would put the magic of the underwater world within reach of millions of people. The aqualung was remarkable because it allowed divers to carry their own air supply in a tank of compressed air and breathe from it at will.
Less than 70 years later, it has never been easier to learn to dive, and air travel has put previously remote and prohibitively expensive destinations within reach of an increasing number of sport divers. There are estimated to he around ten million certified scuba divers in the USA alone, and the sport has developed into a multi-million-pound industry worldwide.
The word 'scuba' is an acronym, derived from self-contained underwater breathing apparatus. I've always felt the word betrays its military origins, and reminds me that for much of history, the motivation for going underwater was connected with warfare. Alexander the Great is reputed to have visited the seabed in a glass barrel at the Siege of Tyre in 332 BC, inspiring earnest debate about how an airtight vessel could have been built with construction materials available at the time. The 13th-century philosopher Roger Bacon described a bell-like device that allowed divers to work on submerged vessels for lengthy periods. Bacon's descriptions of bells are vague, but the principle is simple. A person enclosed in a bell can sit or stand on the seabed with Iris or her head safely in the enclosed air space above--at least until the build-up of carbon dioxide from their exhalations renders the air foul.
Naked divers, such as Greek sponge fishermen who could hold their breath while working underwater, have been documented throughout written history, but the first successful use of a mechanical device to supply someone with air underwater is less easy to date precisely.
During the Renaissance, covert underwater attack was seen as the ultimate strategy, if only on paper. The first printed illustrations of a diving warrior were produced to accompany a 1511 edition of Epitome institutionum rei militaris, originally a work by the fourth-century Roman military strategist Flavius Vegetius Renatus. The woodcuts show men in leather or cloth suits, apparently walking underwater with an air hose leading to the surface. They are suitably armed for combat, and in one picture, the soldier even wears a metal helmet and visor.
In 1551, the Italian mathematician Niccolo Tartaglia published a design for a wooden frame that contained a giant hourglass in which a man could stand. By the end of the century, Buonaiuto Lorini, author of Le fortificatione, had designed several unworkable devices, one of which placed a man on a fixed seat with his head in a leather tube that reached to the surface. It's no more practical than a sketch made by Leonardo da Vinci 100 years earlier that purports to describe a diving suit with which to attack enemy ships unseen. Da Vinci describes a "wine skin to be used to contain the breath", which may be deflated to descend and inflated by the diver in order to rise. He advises the diver to carry a sharp knife so as not to become entangled in the enemy's nets.
By the late 16th century, sketches of diving systems had begun to proliferate. Perhaps the most inventive armchair theorist of all was the Italian inventor Alfonso Borelli, whose designs from 1680 included descriptions of "flippers on the diver's hands and feet in order to swim like a frog". …