amanico[JLC Moderator]
403834
COSC is for the movement NOT ENCASED. If my memory serves me well, METAS is for the movement encased in the watch, right?
A Chronometer has to be certified by an Independant Authority. COSC is. Is is the case for METAS?
I like the idea of a Chronometer Certified. It could also be done by an Observatory.
Now, if you don't care about the Chronometer Title, no problem, you are also right. JLC when they made the Tribute to Geophysic, finely set the balance wheel of the movement, to obtain a superb accuracy. Between one to two seconds per day. But it is not a Chronometer. But it is more accurate than many Chronometers.
Best,
Nicolas