In 1967, TUDOR, who had been supplying the US Navy with divers' watches since the late 1950s, began development of a technical model to replace the Oyster Prince Submariner 7928 reference, which was standard-issue at that time. This new watch needed to meet a set of specifications decreed by the American government and incorporated the results of the latest research into functionality and ergonomics carried out by the brand's engineers. A development phase was launched which resulted in the production of prototypes, as well as a patent for a hitherto unseen function. This ambitious project, which carried the code name "Commando", never came to fruition as the regular TUDOR divers' watch, reference 7016, which replaced reference 7928 in the TUDOR catalogue, was eventually adopted by the US Navy. In 2019, the TUDOR Black Bay P01 model - which stands for prototype 1 - is inspired by a prototype developed as part of this study and kept in the brand's archives, only to have its unique aesthetic brought to life and mass-produced 50 years later.