The Navigator

First issued in 1980, the Navigator was intended as a replacement for the H.S.3 deck watch and was for use in navigational tasks where the date was used frequently - for looking up tide tables for the calculation of tidal heights and times; and in astronomical publications for sun rise, setting and twilight times and for calculation of position lines for celestial navigation.  As well as (more mundanely) for drafting of signals, reports and orders. 

It was based on the standard G10, and specified in two variants - a luminous version with NSN 6645-99-541-7362 approved for use in all departments of the Ministry of Defence except HM Submarines, and a non-lume version NSN 6645-99-541-7363 appropriate for use in nuclear submarines.  The movements in the Navigators were the same as in the standard G10s, which already had a date function; so the only real difference to the G10 was the addition of a date window in the dial.

The lumed Navigator was issued in 1980, 1981 and 1982, and then again in 1994, 1996 and 1997, with batch details as below:

1980 - old logo; SWISS at bottom of the dial; no service code in front of NSN; known serial number range 032 to 560.

1981 - old logo; SWISS at bottom of the dial; no service code in front of NSN; known serial number range 655 to 962.

1982 - new logo in oval; SWISS at bottom of the dial; no service code in front of NSN; known serial number range 1015 to 1199.

1994 - new logo in oval; SWISS MADE at bottom of the dial; appears to be a conversion of civilian G10 with no broad arrow, with the original NSN ground out, the new NSN re-engraved, the Royal Navy 0555 code added and the serial number and year on the side by the crown; known serial number range 002 to 075.

1996 - new logo in oval; SWISS MADE at bottom of the dial; NSN and broad arrow factory stamped on case back; no service code; serial number and year lightly engraved; known serial number range 0004 to 0049.

1997 - new logo in oval; SWISS MADE at bottom of the dial; case back the same as 1996 but with 0555 added above NSN and deeper engraving of serial number and year; known serial number range 015 to 030.

Some lumed prototypes also exist from the early 1990s converted from standard G10s, which bear the entire G10 NSN (6645-99-541-5317) and then 7362 added to denote the conversion.  

The non-lume Navigator was issued in 1980, 1981 and 1996, with batch details as below:

1980 - old logo slightly lower on dial than on lumed version; SWISS at bottom of the dial; no service code in front of NSN; no circled T on the dial, and dial and hands finished in white paint; only one serial number  known - 606.

1981 - old logo slightly lower on dial than on lumed version; SWISS at bottom of the dial; no service code in front of NSN; no circled T on the dial, and dial and hands finished in white paint; known serial number  range 1012 to 1023.

1996 - new logo in oval; SWISS MADE at bottom of the dial; no circled T on the dial, and dial and hands finished in white paint; appears to be a G10 conversion with last number of NSN modified from 2 to 3, with an engraved s/n and date and 0555 prefix above the NSN; known serial number range 003 to 034.

There are also some watches from 1990 which have the non-lume NSN on the back, a non-lumed dial although marked with a circled T, and a white on black date wheel; this combination may not have been an issued watch, though - pictures can be seen on this MWR post.

More details about all the issued navigators can be found in this MWR post.

In 1999 the Pulsar G10 entered service with a date window as standard,  and non-radioactive Luminova which effectively made the need for a separate Navigator in both lume and non-lume redundant.  However, another version of the Navigator was manufactured in 2000 - the "GS2000" - about which there is some debate.  According to CWC and other sources (in the comments section of the HODINKEE article about the 1980 dive watch, for instance!), 500 watches were issued to the RAF, but none have  been definitively seen.  Maybe they are sitting in a box in some Stores somewhere?