Sadly on June 22, 1774, John Day, a carpenter and wheelwright became the first recorded death in a submersible. A bet between Day and Christopher Blake, who noticed his submarines before, was the trigger to attempt the dive.

Day had previously experimented with other builds where he successfully submerged to 9m/30ft before. He was betting he could stay up to 12 hours at a depth of 40m/130ft. Day overestimated the ballast required to bring down his watertight chamber and sank to the bottom with no hope of rescue.

In 1916, Japan, Riichi Watanabi and the blacksmith Kinzo Ohgushi invented the first scuba, the “Ohgushi’s Peerless Respirator. It could be used as a surfaced supplied unit or from steel cylinders filled with compressed air.
The diver had to bite the valve mechanism and the force controlled the flow. In 1919 the British patenting office and in 1920 its counterpart in the US, patented the Ohgushi Respirator.