A mechanical watch owner here: One very important thing to keep in mind is that a mechanical watch needs to be worn always in order to avoid having a winder or the gears losing their accuracy. Therefore, I opted for a "field" automatic watch: Seiko SNZG15J1. Field automatic watches are meant to be worn all the time. The SNZG15 has the Seiko 7S36 caliber which doesn't allow hacking or manual winding. But both features are not really necessary if you wear the watch all the time and willing to accept < 60 seconds worst case difference with atomic time.