Omega Diver 300m Co-Axial Master Chronometer 42mmOverview The Omega Seamaster Diver 300M reference 210. 32. 42. 20. 01. 001 is Omega's current generation dive watch technically the most capable in the Seamaster line's history, and in some measurable respects, more advanced than watches at a higher price point. The 42mm steel case carries a black ceramic bezel with a white enamel diving scale, and retains the conical helium escape valve at 10 o'clock a design element that has defined the Seamaster's