Leonardo was in Venice at the time and the city of Venice was threated being invaded by the Turkish navy. (Keep in mind that Venice is a city surrounded by and built on the water).
Leonardo presented himself as a military engineer and invented the Scuba diving gear as a solution for the Venitian army, so they could have an army of underwater soldiers to fight the Turks. Unfortunately, the Venitians did not implemented Leonardo's idea. They thought it was too wild and crazy.
That is one example of how beyond his time Leonardo really was. It wasn't until centuries later that people thought that the idea of diving underwater with the help of an oxigen gear wasn't a crazy idea.
The first gear-cutting mechanism was designed by Leonardo da Vinci. However, no evidence indicates that it was ever built.
No practical SCUBA gear existed until it was developed by Jacques Cousteau in the 1940's, improving on his aqua-lung design. da Vince was farsighted and speculated about many things, but he did not build usable underwater breathing gear.
Different scuba gear types weigh different amounts. The oxygen tank is the heavy part of the scuba diving gear.
Jacques Cousteau is credited for and I believe invented the modern SCUBA gear for diving, making diving a sport accessible to many.
Scuba was invented by the navy.
Scuba gear
Leonardo da Vinci conceptualized designs for various flying machines, including landing gear, during the late 15th century, particularly around 1485-1490. His sketches, part of his broader studies on flight and aviation, demonstrate his innovative thinking and understanding of mechanics. While he never built these machines, his designs laid the groundwork for future aviation.
A helicopter, a submarine, a battle tank, a gear driven cart, a multiple firing cannon array, and siege engines.
The first gear-cutting mechanism was designed by Leonardo da Vinci. However, no evidence indicates that it was ever built.
Underwater!
Scuba gear
Many scuba stores sell scuba diving cameras. Check a scuba gear stores in your area. This will allow you to compare cameras and get advise from fellow scuba divers.