Leonardo da Vinci’s underwater invention designed around a surface air hose is called a diving suit.
Leonardo described the concept in the early 16th century, when he was studying military and engineering problems for patrons in Venice. The suit included a mask, breathing tubes, and a system intended to let a diver remain underwater while receiving air from above. Some descriptions also associate the design with a hose made from reeds and a means of keeping the breathing apparatus afloat.
The proposal is usually connected with underwater sabotage or reconnaissance, although there is no reliable evidence that Leonardo’s version was built and used in warfare. His drawings were partly concealed or kept secret, which adds uncertainty to the intended application.
The design should not be confused with a modern scuba suit. It lacked modern regulators, compressed-air cylinders, and dependable underwater control. Its historical importance is that it recognized the central engineering problem of supplying breathable air to a submerged person.