Officine Panerai originally supplied the first divers' watches and depth gauges to the Italian Navy back in the 1950's. Now Panerai has created the Luminor 1950 Submersible Depth Gauge, which combines both measuring devices in one instrument. This divers' watch has an automatic movement which is officially certified as a chronometer by the (C.O.S.C.). On top of the chronometer certification the depth gauge calibration has also been individually tested by the Swiss Federal Office for Metrology (METAS). The 47mm case is made of titanium and is water-resistant to 120m. The depth gauge operates from what is essentially an independent movement that is electronic for extreme accuracy and reliablitiy. The depth gauge is actually powered by a lithium battery and can be activated by a push-piece at 10 o'clock. The gauge even has a memory function to record your depth.