A bathyscaphe is a self-propelled vehicle used for deep-sea dives. They can dive deeper than a person with scuba gear and, in some instances, even deeper the submarines.
Made of two main components—a heavy steel crew cabin designed to resist pressure and a float made of air and gasoline tanks to allow the vehicle to dive and ascend—bathyscaphes were first designed by Piccard. His most successful vehicle, the Trieste, was launched in 1953 and dived to 3,150 metres (10,300 feet) with the Rolex Deep Sea Special No.1, which Christie’s will auction this November, strapped to its hull.
Developed as a prototype by Rolex in the watchmaker’s quest for the ultimate diving watch, the Rolex Deep Sea Special No.1’s case, original movement and bracelet are described by Christie’s as being in “perfect working condition”.