How Accurate is Your Zodiac?

[doog]

After 3 weeks on the wrist, my Sea Wolf is losing a fraction over 3 seconds a day when left crystal up overnight, and losing just under 2 seconds a day if left caseback up overnight. Not quite COSC standards, but not too shabby for a nearly 60 year old timepiece. This is better than my Cal 562 1963 Seamaster, which gains about 5 a day, and is quite a testament to the very high standards that Zodiac practised in manufacturing them. It also shows how good a job YuriyV did preparing it before letting me take it off his hands. Really pleased I joined the Zodiac family, they are brilliant watches and, I think, very underrated.

[Butch]

That's not bad! They can be almost perfect depending on movement wear. The SST is even more accurate.

[doog]

 Is the increased accuracy of SSTs down to the 36,000 rate ?

[Butch]

If you meant due to, then yes. Zodiac guaranteed 1 minute per month on the SST.

[doog]

That is mighty impressive. About two seconds a day is getting close to quartz level accuracy from an automatic, I am surprised that Zodiac did not submit the SST to COSC and market then as Chronometers, unless of course they did and I have missed that in the brochures of the time. The rest of the Swiss industry in the 60s and 70s certainly did.

[Butch]

They always had chronometers listed in all the catalogs too. But yes, the SST was extremely accurate.

[YuriyV]

Unfortunately nowadays it is hard to maintain SST's accurate rate due to lack of spare parts. Especially mainspring barrels. High beat movements are very sensitive to lubrication and state of the MS. After huge stress they are very worn or even broken. A lot of efforts needed to return them back to specification.