Hi there,

I have recently acquired two early Heuer / Monnin diving watches.

Watch 1 (W1)-
Black dial with red 24 numerals, cathedral hands, 1st execution bezel.
Dial signed HEUER. 200 METRES PROFESSIONEL. MADE IN FRANCE
Case back stamped 844 on the outside, with serial number 610x.
Case back inside stamped BREVET 503.305 M.R.P. S.A. G. MONNIN. FRANCE
Movement is FE 4611A type, with G. MONNIN FRANCE on the rotor.

Watch 2 (W2) -
Faded orange dial with black mercedes hands. 2nd execution bezel.
Dial signed heuer. 200 METRES professionel. MADE IN FRANCE
Case back stamped 844 on the outside, with serial number 1209x.
Case back inside stamped HEUER-LEONIDAS SA. BREVET 503.305 M.R.P. S.A
Movement is FE 4611A type, with G. HEUER on the rotor.

I am trying to piece together a timeline of these early dive watches. It might not be a fair assumption that all evolution was linear along a serial number path, but here are my queries...

1. When did Heuer switch from the Made in France dials to the Swiss Made dials? Was there some overlap?

2. When was the ETA 2872 movement introduced and the FE 4611A movement finished?

3. Was there an overlap between French and Swiss production?

4. When did the case backs for the orange dial examples get stamped with the catalogue ref. 980.005 (or is there something 'wrong' with a France orange dial and a 844 case back on the same piece?)

I will try to post some photos in the coming days. I would be interested to compare notes with other early era 844-type dive watch owners out there.

Thanks,
Linden