I cannot answer as to why it is not COSC certified but to be honest I think a lot of people get hung up about that anyway. Unless your job or serious hobby I.e. Motor racing or flying requires that range of accuracy I really don't see where it makes a difference to the average guy. If you want pin point to the second accuracy look at your phone. For me the whole thing about a mechanical watch is its intrinsic engineering beauty not its super accuracy.

: Hi All,

: I am new to the world of high qualty watches, but have been
: searching the web for the past few months in order to learn as
: much as possible of this great world that is unfolding before my
: eyes !
: In the search for a watch (I have not owned at watch for the last 7
: years, simply due to the fact that I will not wear a low quality
: watch) - I have fallen completly in love with the TAG Heuer
: ranges. Currently, I am thinking about purchasing the Calibre 36
: Flyback (black/anthrasite wtih leather strap) in a few months,
: when I have the money :-).
: I have read a lot about COSC, and it seems little bit odd to me
: that his particular watch does not have this certification,
: especially consindering it is a 5Hz Zenith El Primera
: movement...Can anyone pls. explain why this is, and also inform
: if it has any relevans at all...