It was with OMEGA's maritime legacy in mind that the brand launched its Planet Ocean line in 2005. Today, the stylish OMEGA Seamaster Planet Ocean 600M Master Chronometer pays homage to OMEGA's dive watch heritage. This model, with its scratch-resistant sapphire crystal, features a black ceramic dial with Arabic numerals and a date window at the 3 o'clock position. The black ceramic unidirectional bezel with OMEGA Liquidmetal diving scale is mounted on a 43.5 mm stainless steel case. Other features include an alveol screw-in caseback and a stainless steel bracelet with patented extendable foldover clasp. The OMEGA Seamaster Planet Ocean 600M Master Chronometer is water resistant to 600 metres / 2000 feet / 60 bar, and has a helium-escape valve. The OMEGA Master Chronometer calibre 8900 at the heart of this timepiece can be seen through the transparent caseback. To achieve Master Chronometer status, it has passed the 8 rigorous tests set by METAS (The Swiss Federal Institute of Metrology).