Swiss metal deck watch in original Mahogany box Circa 1930

Royal Italian Hydrographic Institute deck watch
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A rare deck watch from the collection of the ‘Royal Italian Hydrographic Institute’, made by the Lemania Watch Co. in l’Orient, Switzerland, circa 1930. The numbered case of this watch was crafted from metal and fitted in to a Mahogany box. The original silvered dial features an outer minutes and hour track with Arabic hour numerals, a central seconds dial with Arabic 5 seconds numerals, blued steel hands and is marked Istituto Idrografico R. Marina. The numbered glazed movement is fitted with an anker chronometer escapement, a large chronometer balance and centre seconds.
The dial and movement are signed.
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Diameter: 100 mm (case)
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Signed: B.C.G. Lemania
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B.C.G.
On a Lemania deck watch from approximately 1930, the letters B.C.G. refer to its official Italian military provenance.

The abbreviation stands for Bussola di Calotta a Graduazione, which indicates it was part of the specialised navigational equipment used by the Italian Royal Navy (Regia Marina).

Key Facts About These Markings:

• Official User: These watches were issued to the Istituto Idrografico della Marina (the Navy’s Hydrographic Institute) for use on ships.
• Watch Role: Every Italian Navy ship typically carried two of these issued Lemania watches as part of its essential on board navigational tools.
• Specifications: These models often featured oversized nickel cases (around 103mm), center seconds and frosted gilt movements.
• Case Details: In addition to “B.C.G.”, the case back usually features a unique issue number stamped directly into the metal.

Later British Lemania watches use different codes like H.S. (Hydrographic Service) or 6BB (Royal Air Force), but for the 1930s Italian Navy models, B.C.G. is the definitive mark of its origin.