WHEN American inventor Leonard Norcross tried out his latest gadget he needed a river and a willing test subject.

The year was 1834 and Norcross, better known for agricultural inventions, had been tinkering with a special suit that would enable people to dive deep beneath the waves. It was made of elastic Indian rubber-backed cloth, recently invented by Goodyear, attached to a metal helmet that formed a watertight seal. Hoses connected the helmet to an air supply — a set of bellows on the surface of the water.

When Norcross tried his invention in the Webb River in Maine, in the US, it proved to be non-fatal and allowed his test pilot to walk freely underwater. He applied for a patent which was granted on, June 14 in 1834. It was the first fully enclosed diving suit, using the innovation of elastic rubber to fill the suit with air and keep the diver relatively dry. To counteract the buoyancy, the diver’s boots were weighted down with iron shot.

Norcross was not the first person to make an underwater suit; two other patents had been issued earlier that year. But while his differed from previous suits by using rubber, he built on past inventions, just as inventors after him would continue to refine suits into the modern scuba diving era.

media_camera Leonard Norcross, the American inventor who pioneered the diving suit.

For centuries before Norcross, people had been dreaming of being able to swim or walk freely under the water for more than a few minutes at a time.

Greek philosopher Aristotle described in the 4th century BC how some men used an upturned metal cauldron to go under water because the cauldron “does not fill with water but retains the air”.

According to a 15th century legend, Alexander the Great made a descent underwater in a sealed glass barrel, but he would have suffocated in minutes without an air supply.

media_camera Nick Paspaley, in a heavy diver’s suit, is assisted by his sister Mary as he prepares to dive for pearls in Broome in the early 1930s.

In the early 16th century Italian artist and inventor Leonardo da Vinci sketched designs for a diving suit made of leather. It had a bag-like mask attached to bamboo tubes and connected to a cork float on the surface which allowed the diver to draw breath. He also suggested using a leather wineskin of compressed air which would allow men to move without being attached to the float. There even was a sac for the diver to urinate into and steel rings inside the suit to counteract the pressure. It was designed for soldiers to attack ships from underwater.

Da Vinci also sketched designs for a diving bell. The design, realised by Italian scientist Guglielmo de Lorena, was used by men in 1531 to dive on emperor Caligula’s pleasure galleys beneath the waters of Lake Nemi near Rome, the first-known successful use of a diving bell.

Edmund Halley, better known as an astronomer, drew designs for an improved diving bell in 1691. Part of his innovative system involved men wearing a smaller diving bell on their head, attached by a hose to the mother diving bell, so that they could move free of the bigger craft. But the suit proved impractical until it was improved by John Lethbridge, who, in 1715, completely enclosed the suit to keep in the oxygen. This system was used to salvage cargo from shipwrecks, but also helped with diving for pearls, sponges and coral. Later, it was also used for underwater construction works, such as pylons for bridges.

media_camera Explorer and filmmaker Jacques Cousteau preparing to dive in TV documentary.

French military officer and inventor Chevalier Pierre Remy de Beauve came up with a diving suit design in 1715 which had an enclosed helmet supplied with air from the surface using a bellows pump, but had another hose to extract the diver’s expelled breath.

By the end of the 18th century, diving suits with an enclosed spherical metal helmet were becoming widely used, with improvements to pump technology and valves to allow the air to flow properly, such as the exhaust valve on the helmet invented by Auguste Siebe in the 1830s. Norcross also improved on the airtight suit with his rubberised design in 1834.

In 1865 saw the first experiments using a compressed air tank for diving instead of being tethered to the surface by air hoses. It took decades of tinkering before it became practical for divers to breathe underwater by carrying their own compressed air.

In 1933 Yves Le Prieur invented a valve that could provide air on demand from a compressed air tank, but regulating the air flow was a problem. That was solved when Jacques Cousteau and Gagnan designed the aqualung in 1943.