> My Omega Seamaster gains ~2-3 minutes a month (so roughly 4-6 seconds a day.) That falls within the bounds of accuracy required of a Swiss certified mechanic

> My Omega Seamaster gains ~2-3 minutes a month (so roughly 4-6 seconds a day.) That falls within the bounds of accuracy required of a Swiss certified mechanical chronometer (that is to say, a clock accurate enough for marine celestial navigation) and is pretty good. As a marine engineer I have a genuine and real appreciation of mechanical chronometers, though any working watch/clock I use will always be quartz as for accuracy and price, nothing else comes close. https://en.wikipedia.org/wiki/Marine_chronometer https://en.wikipedia.org/wiki/Marine_chronometer