Before looking at brand or aesthetics, there are three technical specs that genuinely predict how an automatic watch will behave day to day. Here's what they mean and why they matter, with real examples from Cazador's encyclopedia.
This is how long the watch keeps running without being worn or wound. A standard automatic runs 40-48 hours; some in-house calibers reach 70 hours (Rolex Calibre 3235) or even 120 hours (IWC Calibre 32111). The higher the number, the less often you need to reset the time after leaving it in a drawer over a weekend.
30-50m covers splashes and rain; 100m adds worry-free swimming; 200-300m with ISO 6425 certification means the watch has passed real diving tests, not just 'holds up to water.' If you're not diving, you don't need 300m — but the figure tells you your real day-to-day margin.
COSC is the Swiss chronometer standard applied to the bare movement. Some brands go further: Rolex certifies the fully cased watch as Superlative Chronometer, and Omega/IWC put the whole assembly through additional METAS testing. It's not just marketing — it means someone outside the brand verified the accuracy of the complete watch, not just the engine.
Power reserve, water resistance, and certification are the three specs you can objectively compare across different watches, independent of aesthetics or brand prestige. Check these before deciding.