The Rolex Submariner COMEX (Compagnie Maritime d'Expertises) is a special version of the Rolex Submariner that was made for the French diving company, COMEX. This version of the watch was made with a helium escape valve, which is a small device that allows helium to escape from the watch case during saturation diving, where the divers spend extended periods of time under pressure in a helium atmosphere. This feature prevents the crystal from popping out due to the pressure difference between inside and outside of the watch case. The COMEX Submariner is also characterized by its thicker case and the engraved "COMEX" on the caseback. These watches were produced in very limited quantities and are highly sought after by collectors and enthusiasts due to their association with the professional diving industry and their unique features.
