I got this ww2 timepiece from an retired royal navy watchmaker, marked HS4 on the back and H.Golay and Son Ltd on the dial. H.S 4, as I understand, denotes aircraft instrument clock but after the war, according to the watchmaker, was used as a deck watch along side with other H.S3. It has a rotating bezel marked 0 to 360 and I have been wondering if anybody know what it was for. It has a Swiss Unitas movement, commonly found in other deck watches from the same era.

Case back

movement

Hello again, Lau Siew Ming.

While your Fleet Air Arm Instrument Watch could have seen post-war duty as a deck watch, I don't think it would have been used as such for long. Otherwise, it would have eventually been re-marked with NATO codes on the back.

The bezel would have been turned to the position of the hour hand to mark the time of take off so that the pilot would have an idea of how long he had been in the air. The time of take-off was of use for navigation and fuel consumption.

This is an eye catching timepiece. The roman numerals and time of trip bezel make an attractive contrast.

The black bezel with locking nut is interesting. Maybe someone knows, where all H.S.4 watches set up with locking bezels?

Best regards,
Greg

The bezel is marked off in 360 degrees so I think it might be more for a compass then a watch,in a compass you would set the bezel ring for magnetic declination by rotation the bezel with the crown and then lock it in place.There is no need or use for this in a watch that I know of. I might be very wrong but I think that's a watch fitted into a compass case.

Here is something that I think most everyone who is fascinated by watches and clocks would be interested in knowing.

I don't know if the 360 degree outer dial on the illustrated watch was actually meant to be used for the following, but you can use any analog watch as a compass - of a sort. Assuming you are in the northern hemisphere and your watch is not set to daylight savings time, hold the watch flat and turn it until the hour hand is pointing at the sun. South will be on a heading halfway between the hour hand and the 12:00 marker. With a watch like this one, you could then rotate the watch to align the outer dial with the direction you just established and being careful to hold it in that alignment you could then determine a relatively decent compass heading. This will not be all that exact like a real compass but it is a nice trick to know for survival situations. On the other hand I would think it would be much simpler to just use the compass in the aircraft unless your machine has crashed and you are trying to travel light to find your way back to your side of the lines and you don't want to be lugging around a big heavy instrument from your cockpit - assuming it survived the crash. Another little trick is that if your watch has run down and stopped and you don't know the time, if you have a working compass you can do the above trick in reverse order to set the watch to the correct time - more or less. It will be off by at least a few minutes as you can not do this exactly enough but it will be close.

The reason this works is a watch is nothing more than an instrument to mark the 24 hour rotation of the earth around the sun. The sun rises in the east and sets in the west and mid-day is at 12. Think about the geometry for a while and things will start to make sense, or if it makes your head hurt, just trust me

As I said though, I have idea whether this is the reason for the 360 outer compass dial or whether the case is really a pocket compass case.

I concur with Greg that it should have a NATO code if has been used post-war for any prolonged period. However, I have also never seen a double issued HS4. From the same watchmaker I also obtained a Hamilton HS3 and was told that some of these Hamilton ww2 watches were in service up to mid 70s, which is really quite amazing for a watch. Would be interesting to confirm this if they were any service document to sight.

I am also more inclined to believe that the 360 deg marked rotating bezel is for navigation purposes but still clueless as how it was used.

Jim's explanation of watch as a basis compass is very interesting, something worth knowing.

If you find yourself in the southern hemisphere you can still use a watch as a compass but you have to reverse things to account for the different angle of the sun as seen from that region.

Here is another example of this time piece type by Zenith. The marking reads "TIME OF BEACON NORTH" and "SECS." It is also a HS4. I received these images from another collector several years ago to identify and have to date been unable to do so. This time piece was used for navigation but exactly how is not clear to me. On the dial of this example is the number 2355. On the example that Lau shows I see the numbers 35, I wonder if this is the serial number?

The number on the dial is 835 (8 got hiddend under the second hand) and the same also appear on the inner caseback and the rim of the case. They don't look factory applied and I assume it is the issue s/n.

Here is another H. Golay H.S. 4 to add to this topic thread:

#315 but with a DOXA movement instead. I have seen a few dial variations to the examples seen here. One other variation I have seen is the markings "A W" with a braod arrow between.

I find it facinating how one can navigate using
this timepiece. And such an attractive one at that. Regards all. M

Rear markings

Movement

Close up dial markings

Hi Michael, I just noticed...Your watch wasn´t delivered like that, case(side), caseback, movement and dial should have the same number, I suspect yours was a put-together, from a couple of other watches

Here´s mine to compare:

Hallo friends
here a a few similar watches H.S. 4 assembled by Golay & Son with movements by EMT Tissot, Doxa and Zenith.

. Gruesse/Regards/Salute Konrad Knirim
PS: Have a look at my books on Military Timepieces:
. http://www.knirim.de

I found another, but this time with the original Bakelite holder for the watch-case, which was screwed into the cockpit. The watch could be removed after flight and the holder would remain on the dashboard.

Thank you Werner for the excellent photographs of your exceptional example of the H.S.4. I like seeing the original mounting units. These are often missing.

I fully agree with Gregg,Werner. Nice watch and the photos nicely done !!!

Thank you Greg and Tom, I appreciate the feedback, it gives one a feeling that it's not all senseless to post here

Werner;are you going to post your Kieninger and Obergfell Kriegsmarine Nord See ships clock? It's a real beauty!!!!

Number 267 can be added to the list. Recent acquisition. Dial marked with “A^W” possibly for Avigation/Aviation Watch? Did the British use the term Avigation as the US did in that late 30’s era…? From all my research I’ve found 10 examples marked with the “AW” all are below the 289 serial number range…
Timepiece used in conjunction with the R1147 receiver beacon used by the FAA at that time. Short lived.