Giovanni Panerai (1825-1897) founded Officine Panerai in 1860 in Florence on the Ponte alle Grazie. At the turn of the twentieth century the watchmaker’s shop moved to its current location in Piazza San Giovanni where it resides today, it was renamed Orologeria Svizzera. In the following years Giovanni Panerai's grandson Guido Panerai (1873-1934) expanded the business by specializing in the production of high precision instruments as well as watches and Officine Panerai had excelled to become the official supplier to the Regia Marina, the Royal Italian Navy.
Officine Panerai’s innovative techniques flourished during tough political circumstances. The Italian Navy needed a reliable and sustainable instrument during wartime efforts. It was in 1916 that the patent was introduced for Radiomir, a radium-based powder that gives luminosity to the dials of sighting instruments and devices. Later Officine Panerai changed this material to Luminor which had the same qualities as Radiomir but not as dangerous as the original radioactive material. Radiomir became a key component for Officine Panerai watches due to its high visibility and underwater adhesive qualities. Today however, Radiomir relates to the case rather than the self-luminescent material of the dial for vintage watches.
During the Second World War, the Officine Panerai productions were standard issue tools for military personnel such as Italian Navy frogmen, Marina Militare, as well as the German Navy, the Kriegsmarine. From the late 1930’s to the 1980’s, Officine Panerai developed diving watches alongside other military necessities such as compasses, gauges, and torches. Almost all diving watches used movements and waterproof cases made exclusively by Rolex to ensure resilience and accuracy under extreme conditions.
The reference 2533, the first prototype for the Radiomir was produced in an extremely small quantity. The second to be produced was reference 3646, in production from 1938 until the 1950’s and produced in various versions named Type A to Type G, each bearing unique aesthetics. Initially, the reference 3646 had a Rolex dial and was called the California Dial, including Arabic and Roman numerals. It was only later that Officine Panerai replaced these dials.
Type D includes distinctive features such as the engraved case back reading the unit that this military watch belonged to, the date, as well as the initials of the original owner. From these engravings we can see that watches were used by German Kampfschwimmer units, or combat swimmers during the Second World War. Furthermore, this model has an early unsigned dial which is evidence of its remarkable passage in time.
Similar watches of the 3646 / Type D number group are featured in Vintage Panerai, History1 and History2 by Ralf Ehlers and Volker Wiegmann, 2012.