Quick guide to Berthoud & UG 38mm waterproof monoblocco chronographs

Some of the most wanted references of UG are the 38mm waterproof (or pressure back or monoblocco) chronograph. Made in (very) limited numbers and not many survivors. The case is very similar to the famous Bovet/Vetta cases but they are certainly not the same. Unfortunately it is still unknown who produced this cases.



These watches were made in 8 references but I would not be surprised if a 9th one was made - reference 7076 - but so far I have not found a (trace of a) survivor. The below table explains the differences but the general idea was quite straightforward: 2 brands, 3 different bezels and 2 different (type) of movements.



My estimate of the total production is 550 examples of which I can identify in total 23 survivors.

Some explanation on the table below (which is part of a much bigger table which is WIP).
7065: reference
Brand: obvious
Sala: these references are not mentioned in Sala
Case: case material, in this case stainless steel
Mov: movement reference
Mov ser: these references don't have numbered movements
Pushers: round
CB: caseback, in this case a snapback (so: click)
Batch: some references are made in more batches. Only ref 7069 was made in more batches. The one in this overview is batch 2 of the 2.
KS: known survivors
Tank: batch size following the tank formula (see: https://en.wikipedia.org/wiki/German_tank_problem). Sometimes I only know the 1st 3 digits of the serial so in that case the tank formula is not applicable. Tank number for the the 8 references combined is 521 pieces.
Low Fit: how tight is the fit of the serial numbers
High Fit: see low fit
Prod: my assumption of the production
KSR: known survivor rate
From/to: estimated range of serial numbers. The numbers which I have recorded do fit in this ranges.



As always: more examples are welcome.

Updated table:

This was probably one: https://www.ebay.nl/itm/177796724066 however extremely rude seller which was insulted when I asked about the numbers and size. Anyway: wrong caseback and the chance of finding a correct one is close to zero

Yah I was trying to get the exact same information, without any luck 😄
When I asked if the watch was running I got very rapid response, when I asked (3 times) for photo of inside caseback, nothing.
That, combined with the fact that the auction description said "N/A", put me off bidding. Too bad, as I kinda like the dial. Hour and minute hands wrong also, maybe other stuff. But cool dial.
I wonder if the buyer knew about the caseback. I wonder if you could make a successful return in this situation. It was listed as "Pre-Owned Good" condition, which is a preset catagory by ebay, with the following preset ebay definition: "This item has been gently used but is in good condition. It might have a few signs of wear, like light scratches or tarnishing. All imperfections should be shown and described in the seller’s listing."

Interesting.... This 7066 sold for EUR 9.750 in May 2024 https://www.dorotheum.com/de/l/9045479/ and was now sold at ebay. Asking USD 9.000 and best offer accepted https://www.ebay.com/itm/306743631229

cool watch. it was hard to get a feeling for what the dial condition looked like IRL from the pics. I wonder what the actual sold price was.