Is a COSC Tested Movement The Best In The Watch World

[padi56]

With so many today on forum with accuracy OCD its most important to remember that a "COSC certified chronometer" is not the Holy Grail of watchmaking. With the high quality of modern day robotised manufacturing, this test is not that important in reality. As today most decent modern watches from all countries even some from China like the Seagull movements, when adequately adjusted, should be able to match the performance specified by the now quite antiquated Swiss COSC test even the newer Rolex introduced -2+2 spec.

A chronometer certificate is not a guarantee of future accuracy for life only a certification that the bare uncased movement was tested at the COSC and passed at time of testing same for the new Rolex machine -2+2 test. Watch movements that have been certified can get out of adjustment and still perform quite poorly outside the COSC spec or the -2+2 spec. Movements that are not certified could still exceed the COSC standards with just simple regulation.Many of todays manufacturers may have simply chosen to bypass the expense of the certification process its quite expensive to test every single movement. But today IMHO the COSC is little more than a pure marketing tool and means little in actual performance only the fact its been tested at that time.Now when the thousands of movements that get tested and then shipped back to the manufactures those that have passed plus the ones that fail yes some do fail even ones from Rolex.The failed movements are perhaps re-oiled re tested on a machine then shipped back to the COSC to test again.Now a lot could happen to any movement on its way from being certified shipped back then stored then finally cased.In the case of Rolex they must have many thousands in store waiting to be cased then shipped around the world to the various ADs

The term "Superlative Chronometer" is a now trademark of Rolex. The addition of the word "Superlative" in front of the official designation of Chronometer is merely a Rolex marketing angle to give a more distinguished sound to the chronometer status of their products . As all watches that have earned the privilege of bearing the official Swiss designation of "Chronometer" have to meet the exact same COSC standards. Any words added before or after the official designation of "Chronometer" are merely more marketing which Rolex is very good at.There are not any different grades or levels of chronometer certification,for movements of Rolex size but Rolex would like you to think there are.


When thinking of accuracy its very important to remember that even when a mechanical watch is allowed to vary by COSC standards +6/-4 seconds per day, that does not mean it will consistently vary by that high or low amount each day. Mechanical movements that self regulate say by resting in different positions over night its very rare for this to happen.All Mechanical watches are noticeably affected by the gravitational pull of the Earth. It only takes a performance distortion of 1/1000th of a percent for a mechanical watch movement to be one second less accurate in a day. So to get any mechanical watch to self regulate with zero tolerance is IMHO something that's very very rare maybe one it quite a few thousand or even million

Likewise, "Certified Chronometer" also means nothing different than just "Chronometer." It is a redundant phrase--since Chronometer status is the certification the certified is just more pure marketing, and you know what they say about marketing well it often baffles brains.