Omega
Seamaster 300 Coaxial Black dial - Fullset

Omega Seamaster Professional Diver 300M Co-Axial reference 212.30.41.20.01.002, 2012 Full Set example, 41 mm stainless-steel case, black wave-pattern dial with applied indexes and luminous material, skeleton hour and minute hands, central seconds, date at 3 o’clock, unidirectional rotating bezel with black 60-minute insert, sapphire crystal, screw-down crown, helium escape valve at 10 o’clock, screw-down caseback decorated with the Seamaster hippocampus, original water resistance rated to 300 metres, Omega stainless-steel bracelet with safety folding clasp and diving extension, Omega calibre 2500 Co-Axial automatic chronometer-certified mechanical movement operating at 25,200 vibrations per hour, 27 jewels, approximately 48-hour power reserve after full winding, watch supplied with its original Omega box and documents, inspected and authenticated by the Mostra workshop, accompanied by a Mostra Certificate of Authenticity and covered by Mostra’s 3-year warranty.

“The Seamaster did not become a legend because it always looked the same. It became one because Omega preserved the same idea for decades: creating a watch capable of living beside the water, then beneath it, without ever ceasing to be a watch one wants to wear every day. From 1948 to professional diving, from the Seamaster 300 to the Diver 300M, its history is the story of robustness gradually becoming elegance.”

The 2012 Omega Seamaster Professional Diver 300M 212.30.41.20.01.002 belongs to one of the most appealing generations of Omega’s modern diving watch. Its black wave dial, black bezel and 41 mm case preserve the visual identity established by the Diver 300M during the 1990s, while the Co-Axial calibre 2500 places it firmly within Omega’s mechanical renewal at the beginning of the twenty-first century. It therefore occupies a balance increasingly appreciated by collectors: modern enough to offer sapphire crystal, an original 300-metre rating, automatic chronometer performance and the Co-Axial escapement, yet close enough to earlier Seamaster Professional watches to retain their slimmer proportions, lighter bracelet and especially the black wave-pattern dial that became one of Omega’s strongest signatures.

The Seamaster story begins in 1948, when Omega transferred part of its wartime experience with robust, moisture-resistant watches into a civilian watch designed for active life. In 1957, the Seamaster 300 joined the Speedmaster and Railmaster in Omega’s famous professional trilogy and firmly established the Seamaster name in diving. After decades of development in professional and saturation diving, the Seamaster Professional Diver 300M appeared in 1993 with lyre lugs, a scalloped bezel, independent helium valve, skeleton hands and wave-pattern dial, creating a new identity that would become one of the pillars of modern Omega. Reference 212.30.41.20.01.002 retains exactly that language. Its 41 mm stainless-steel case has enough presence for a true diving watch while remaining noticeably more restrained than many contemporary models. The lyre lugs and alternating polished and brushed surfaces prevent the case from feeling excessively heavy and give the watch the refined profile associated with Omega. The black wave dial, applied markers and luminous skeleton hands provide excellent readability, while the date at 3 o’clock brings genuine everyday usefulness without disturbing the character of the display.

The unidirectional black bezel measures elapsed time according to the traditional safety principle of a diving bezel, while the helium escape valve at 10 o’clock recalls the far more specialised world of saturation diving. The screw-down crown, caseback and sapphire crystal contributed to an original 300-metre water-resistance rating. On a 2012 example, present-day use in water should naturally depend upon a recent inspection and pressure test rather than the historical specification alone. The caseback carries the traditional Seamaster hippocampus, maintaining the connection with decades of Omega watches designed around the sea.

The stainless-steel bracelet reinforces the versatility of the watch. Strong but less massive than many current diving bracelets, it keeps the Seamaster balanced and comfortable, while its safety folding clasp and diving extension reveal its professional origins. This is one of those technical watches that can genuinely remain on the wrist throughout an entire day: serious enough for demanding use yet sufficiently refined to feel entirely natural far from the water. Inside works the Omega calibre 2500 Co-Axial, one of the most significant movements in the manufacture’s modern history. It operates at 25,200 vibrations per hour, contains 27 jewels and provides approximately 48 hours of power reserve after full winding. Chronometer certified, it offers automatic winding, hacking seconds and quick-set date. Its defining feature is the Co-Axial escapement, derived from George Daniels’ work and adopted by Omega to reduce friction within the escapement and promote long-term stability.

This movement gives the 212.30.41.20.01.002 a distinctive position within the Seamaster chronology. Visually, it preserves the essential signatures of the classic wave-dial Diver 300M; mechanically, it already belongs fully to the Co-Axial era. It therefore forms a bridge between two generations of Omega, respecting the identity of the past while clearly anticipating the technical direction of the modern manufacture. Its 2012 Full Set status further strengthens its appeal. The original Omega box and documents preserve a direct connection with the watch’s first sale and become increasingly meaningful as this generation moves into neo-vintage territory. Yet the real strength of this Seamaster remains its usability: a black dial that works with almost anything, a balanced 41 mm case, a useful date, a robust steel bracelet and an automatic calibre requiring little attention once the watch is on the wrist. Choosing this 2012 Omega Seamaster Professional Diver 300M Co-Axial 212.30.41.20.01.002 Full Set from Mostra means benefiting from more than forty years of experience in collectible watches, our highly regarded integrated watchmaking workshop in Aix-en-Provence and one of the largest selections of high-end pre-owned watches in the South of France. Case, bezel, wave dial, hands, sapphire crystal, crown, helium valve, bracelet, clasp and original documents are examined, while our workshop checks the calibre 2500 for rate, amplitude, automatic winding, date operation and power reserve.

Mostra’s verified customer reviews carry a 5-star rating, reflecting a relationship based upon expertise, transparency and long-term support. This Omega is supplied Full Set with its original box and documents, accompanied by a Mostra Certificate of Authenticity, inspected by our workshop and covered by the Mostra 3-year warranty. The 2012 black wave-dial Seamaster Diver 300M ultimately brings together more than sixty years of evolution: the water-resistant watch of 1948, professional diving, the emblematic waves of the 1990s and twenty-first-century Co-Axial technology in one watch. A Seamaster technically conceived for the sea, whose greatest talent may still be making ordinary everyday life remarkably easy.