circa 1994, the signed black dial, 32mm diameter, with Tritium indicator, white Arabic numerals, luminous hour markers and hands, centre sweep, date window at 3 o'clock and chemin de fer chapter ring with SWISS MADE below, 7 jewel ETA quartz movement calibre 955.122, matte non-reflective case, 35mm diameter (39mm including crown) with fixed wire lug bars, verso snap on with screw down battery hatch, engraved 6645-99 5415317 7362, to an aftermarket black and white striped nylon NATO style strap with steel buckle

The 'Quartz G10’ was the first quartz watch supplied to the British Ministry of Defence (MOD). Its name is a reference to the form G1033 which needed to be completed before the watch could be issued.

The 'Quartz Navigator’ was intended as a replacement for the old H.S.3 deck watch, to be used for navigational tasks where the date was required, such as referencing tidal tables and phases of the moon. It was based on the standard G10, but had the additional date window to the dial.

In the early 1990s, the MOD commissioned several small batches of ‘Navigator’ watches. These were believed to be prototypes, created by adding a dial with a window to an existing G10 (the G10 movement already had a date wheel, although the dial had no date window) and re-engraving the numbers on the back. The G10 NATO Stock Number (NSN) is 6645-99-5415317, whilst the Navigator NSN is 6645-99-5417362.

This example of a G10/Navigator prototype is an unusual piece and as a result is much sought after by collectors.

The NATO numbers engraved to the back of this example relate to:

6645 - NATO stores code for military watch

99 - UK issue

5415317 - G10 field watch

7362 - last four digits for a Navigator watch - applied to denote the conversion.

(With grateful thanks to Jonathan Hughes - CWC addict - for his assistance in the cataloguing of this lot)