Submariner chronometer or no chronometer

[Fhfoomelaka]

I am about to look for for a submariner watch, question is how accuracy difference between a chrometer certified and non chronometer certified?

[daytona 6263]

I am about to look for for a submariner watch, question is how accuracy difference between a chrometer certified and non chronometer certified?

All Rolex oyster watches are now COSC certified, before with watches like say the non date sub that was not tested.,but they had exactly the same movement as the Explorer that was COSC tested and exactly the same accuracy.Today it costs quite a bit of money to test the bare uncased movement at the Swiss COSC so many manufactures don't send watches for testing.The Swiss COSC only tests movements at their barest functional level.And all movements are machine wound Rolex have there own machine at the Swiss COSC because hundreds at a time are wound by the winding stem.All automatic watches have there winding rotors removed.,because the machine that winds them that fast it would damage the highly geared automatic winding mechanism.Even dial and hands are removed special ones are fitted at COSC test centre.Movements are checked every 24 hours by electronic camera linked to central computer.Rolex has a special machine to test its vast quantities of movements. These are loaded into magazines like bullets.,the machine extracts the movement, reads it, winds it and returns it to the magazine.And some of you guys worry about winding your watch manually.The maximum daily rate during the first 10 days of testing could be as much as +10 seconds over the 15 days testing but a pass is a average of - 4 +6 secs over 24 hours.Now this COSC test now is quite antiquated and now around 95% of movements tested pass the test first time.Truth be told most modern movements any brand and from any country,with some very careful regulation could easily past the Swiss COSC test.IMHO today the Swiss COSC test now is little more now than a pure marketing ploy and only proves pass at time of testing only.

[hypersocial]

Thanks for the write up. I learned new knowledge from this!

All Rolex oyster watches are now COSC certified, before with watches like say the non date sub that was not tested.,but they had exactly the same movement as the Explorer that was COSC tested and exactly the same accuracy.Today it costs quite a bit of money to test the bare uncased movement at the Swiss COSC so many manufactures don't send watches for testing.The Swiss COSC only tests movements at their barest functional level.And all movements are machine wound Rolex have there own machine at the Swiss COSC because hundreds at a time are wound by the winding stem.All automatic watches have there winding rotors removed.,because the machine that winds them that fast it would damage the highly geared automatic winding mechanism.Even dial and hands are removed special ones are fitted at COSC test centre.Movements are checked every 24 hours by electronic camera linked to central computer.Rolex has a special machine to test its vast quantities of movements. These are loaded into magazines like bullets.,the machine extracts the movement, reads it, winds it and returns it to the magazine.And some of you guys worry about winding your watch manually.The maximum daily rate during the first 10 days of testing could be as much as +10 seconds over the 15 days testing but a pass is a average of - 4 +6 secs over 24 hours.Now this COSC test now is quite antiquated and now around 95% of movements tested pass the test first time.Truth be told most modern movements any brand and from any country,with some very careful regulation could easily past the Swiss COSC test.IMHO today the Swiss COSC test now is little more now than a pure marketing ploy and only proves pass at time of testing only.

[Fhfoomelaka]

Thanks a lot. So the myth is cleared.

[daytona 6263]

Thanks for the write up. I learned new knowledge from this!

Thanks a lot. So the myth is cleared.

My pleasure to tell you the real facts.