Citizen Promaster Marine Eco-Drive Diver's BN0158-18X 200M Men's Watch An isolated, self-sustaining timepiece that’s far more accurate than others in its league is a remarkably fascinating idea to any serious watch collector and Citizen seems to have read their mind this time. This one is going to take away all the frustrations you accumulated over the years with mechanical diver pieces; the Eco-Drive runs all by itself, provided you feed it with an hour’s worth of bright light every day for the first couple of weeks after you get it in your.