The historical record is awash with examples of early peoples seeking to explore the underwater world. In a section of the ancient Greek text Problemata, which may or may not have been written by Aristotle around 360 B.C., the author hypothesizes the use of a kind of diving bell, an inverted “kettle” filled with air to give sponge divers an underwater base of operations for extended dives.
Leonardo da Vinci, for one, claimed to have figured out how a person could remain submerged for an extended period of time – but also claimed he would never publish the details of this information, “because of the evil nature of men who practice assassination at the bottom of the sea.”
During Alexander the Great’s siege of Tyre in 332 B.C., enemy divers continually severed the mooring ropes of Alexander’s ships and set them adrift to crash into each other. Though no record of the siege mentions the use of a diving bell, a legend emerged of Alexander being lowered into the harbor in a glass barrel or jar for several minutes to observe the goings-on. For centuries thereafter, versions of this tale were celebrated in texts and paintings from Britain to India.
One of the first actual uses of the diving bell was recorded by Francesco de Marchi of Bologna, who, in 1535, used a primitive one-person diving bell to explore the sunken wrecks of the Emperor Caligula’s fabled Lake Nemi ships. By now, the Western world’s leading thinkers had begun to envision a kind of underwater boat that could move under propulsion. Leonardo da Vinci, for one, claimed to have figured out how a person could remain submerged for an extended period of time – but also claimed he would never publish the details of this information, “because of the evil nature of men who practice assassination at the bottom of the sea.”
In 1775, the young American David Bushnell, with encouragement from both Benjamin Franklin and George Washington, devised the Turtle to attack the British warships blockading colonial ports.
In 1578, seven decades after da Vinci’s death, the English mathematician William Bourne published his own idea for a submersible in the book Inventions or Devices, which included a description of “a shippe or boat that may goe under the water unto the bottome, and so come again at your pleasure.” Though he included no drawings or models, Bourne described how the craft – essentially a wooden boat covered in oiled leather – could be raised or lowered in by filling and emptying ballast tanks, and how its occupants could breathe by means of a hollow mast protruding upward.
The first submersible boats to be made to Bourne’s description were conceived by Dutch physician Cornelius Drebbel, who tutored the children of King James I and served as “court inventor.” While Bourne had hypothetically solved the problems of buoyancy and air supply, Drebbel added a solution to how the boat could be propelled: A crew of oarsmen, if the boat were properly sealed and ballasted, could drive it. Few records of Drebbel’s design remain, but he built and successfully tested at least three of these submersibles – the largest of which carried 16 passengers and was demonstrated in front of King James and several thousand spectators. The boat stayed submerged for three hours, cruising at a maximum depth of about 15 feet.
Drebbel’s invention impressed King James – who rode along for a test dive beneath the Thames – but England’s Royal Navy reacted to these demonstrations with indifference, establishing an unfortunate precedent. For the next three centuries, while the English continued to dismiss the submarine’s potential, their enemies developed and refined the submarine as a means of attacking the world’s most powerful navy. In 1775, the young American David Bushnell, with encouragement from both Benjamin Franklin and George Washington, devised the Turtle to attack the British warships blockading colonial ports. Small and cumbersome, propelled by two screw propellers, the Turtle proved too difficult to operate; it failed in its mission to blow up the HMS Eagle in New York Harbor and was later sunk. It was, however, the first documented use of a submarine in combat.
The next great innovator in submarine development was the Irish-American artist and engineer Robert Fulton, who spent many years in Europe and grew to loathe the Royal Navy – which he, an Irish nationalist, believed was choking off freedom and commerce around the world. By the late 1790s, Fulton had developed plans for an undersea boat he called the Nautilus. Sheathed in copper over iron ribs, the Nautilus was a cigar-shaped craft, 21 feet long and more than 6 feet at the widest, powered by a hand-cranked propeller. Horizontal fins controlled the angle of dive, and a hollow iron keel served as its ballast tank. Above deck, the Nautilus had several new features – a fan-shaped sail that could be deployed to help propel the boat when surfaced; a periscope that would allow an underwater observer to see above the horizon; and a small observation dome that presaged the modern conning tower. Bottled, compressed air allowed the manned craft to remain submerged for up to five hours, and a snorkel could be extended to supplement this supply.
The Nautilus was designed to carry an explosive charge Fulton called a “carcass,” also commonly known as a “torpedo,” that could be attached to the hull of a ship and detonated from a distance, making it an ideal weapon to break the Royal Navy’s blockade of France. After successful demonstrations of the Nautilus in the Seine and the English Channel, Fulton offered to make submarines for the French – who declined, for both practical and moral reasons. A human-powered submarine was simply too slow, and its range too limited, to be useful in naval combat – and the French Ministry of the Marine considered the submarine an underhanded tactical weapon, fit for pirates. Fulton lent credence to this idea when he asked for himself and his men to be commissioned as officers in the French navy, officially recognized as belligerents, to avoid being executed if they were captured.
Rebuffed by the French, Fulton apparently shrugged off his hatred of the British and offered to sell his plans to Prime Minister William Pitt, who encouraged a public demonstration of the stealth attack. This kind of warfare was promptly denounced by other Britons as cowardly, an attitude later summed up by John Jervis, 1st Earl of St. Vincent and admiral of the fleet: “[Pitt] is the greatest fool that ever existed to encourage a mode of war which they who commanded the seas did not want and which, if successful, would deprive them of it.”