Omega launched the Seamaster in 1948 to commemorate its 100th anniversary. The first Seamaster was a civilian wristwatch derived from the CK 2292 supplied to the British Royal Air Force during WWII, but with better water resistance: a dedicated O-ring gasket around the caseback (rather than lead-and-shellac) that made it one of the first truly reliable waterproof automatic watches. Through the 1950s the Seamaster remained primarily a dress-waterproof watch for active civilians, sold as a more affordable alternative to the Rolex Submariner.
The pivot to professional diving came in 1957 with the launch of the Seamaster 300, Omega's first true dive watch (200m at launch despite the name). It was adopted by military units including the British Royal Navy and became the first of a continuous Seamaster dive-watch lineage. In 1970 Omega launched the Ploprof (Plongeur Professionnel), a 55mm steel monobloc-cased watch with a unique left-side crown protector, rated to 600m and designed specifically for COMEX saturation diving. The Ploprof introduced a helium release valve architecture with an internal safety piston.
The modern diving Seamaster arrived in 1993 with the Seamaster Professional 300M, known universally as the Diver 300M. A 41mm steel case, wave-pattern dial, helium escape valve at 10 o'clock, and co-axial Master Chronometer movement defined it. In 1995, the Diver 300M became Pierce Brosnan's wristwatch as James Bond in GoldenEye, and every Bond actor since (Brosnan, Craig, and into the 2020s) has worn a Seamaster Diver 300M on film. The Planet Ocean (2005), the dressy Aqua Terra (2002), and the updated Seamaster 300 heritage reissue (2014) complete the modern collection.
Technical innovations have run in parallel with the expansion of the line. The co-axial escapement developed by George Daniels was adopted across the Seamaster from 1999 onward, eliminating the need for escapement lubrication on the impulse face. From 2015 onward every major Seamaster reference has been Master Chronometer certified, meaning the movement meets METAS standards for anti-magnetic resistance to 15,000 gauss in addition to COSC accuracy. Retail today ranges from USD 5,400 (Aqua Terra steel) to USD 7,000-8,000 (Diver 300M and Planet Ocean) to USD 25,000+ (Ploprof titanium) and over USD 100,000 for jewellery-set and platinum references. The Seamaster is Omega's best-selling family and one of the most recognisable dive-watch silhouettes in watchmaking.
