Monochrome Watches
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The Omega Seamaster Ploprof 1200m Summer Blue, The Return of An Icon (Live Pics & Price)

A new generation of Ploprof on the occasion of the Seamaster 75th anniversary.

| By Xavier Markl | 6 min read |
2023 Omega Seamaster Ploprof 1200m

Part of the Seamaster 75th anniversary collection, Omega had to release a dedicated version of one of its most iconic dive watches, the Ploprof. With its oversized dimensions, distinctive asymmetrical shape, giant crown guard and unique crown placement, this professional diver truly stands apart. As you would expect, the new Ploprof comes with the same treatment as the other Seamaster 75th anniversary models including a compelling gradient blue dial. But there is more. What we have here is a new generation Ploprof, with a new case design. Here’s what you have to know. 

The history of the Ploprof is connected to the development of deep-sea saturation diving in the late 1950s to answer the needs of various industries such as offshore oil and gas exploration, underwater construction, scientific research, and underwater welding or inspection. The technique enables divers to perform complex and time-consuming tasks at depths that would be otherwise inaccessible using conventional diving methods. For divers, it involves living in a pressurized environment breathing specific gas mixtures (including helium, oxygen, and sometimes nitrogen) that saturates the blood and tissues of divers.

The Seamaster 600 Ploprof and the September 1970 COMEX test at -253m off Ajaccio, Corsica.

The development of saturation diving made the need for watches that could perform at great depths a matter of life and death. In particular, saturation divers breathe different gas mixtures containing helium. Helium being a very small gas molecule, it can penetrate the seals of a watch, gradually accumulating inside the watch case during these prolonged periods in pressurized environments. During the reversion to surface pressure, the helium gas trapped inside the watch does not escape quickly enough due to the differential pressure between the inside and outside of the watch case, which can create structural damages.

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In the late 1960s, Omega started to cooperate with the French diving specialist company, COMEX, to develop watches for saturation diving in the frame of a major research project, Ploprof (standing for Plongeur Professionel, Professional Diver in French). Omega developed two kinds of prototypes following the same requirement specifications. Two Ploprof projects coded internally ‘Ploprof 0’ and ‘Ploprof 1’ that would ultimately become commercial models. 

The Ploprof 1 prototype gave birth to the Seamaster 600 Plongeur Professionnel with its quirky asymmetrical design – the PloProf as we know it today. The model debuted commercially in 1971/1972. To craft an impenetrable case, Omega machined a Monobloc case with a specific methid of fixing the glass that would not let any gas in. 55mm x 13.5mm, this beast of a watch was rated water-resistant to 600m, but it was tested down to 1,300m. Its unique set of characteristics included its chemically hardened mineral glass, its dial layout, its imposing crown protection and its bezel locking device. The rotating bezel is bi-directional but it can only be turned while pressing the red pusher. Last but not least, the watch was also fashioned out of Uranus steel, an innovative alloy known today under the name Inox 904L.

An original internal Omega document showing the use of Uranus Steel (matière, meaning material), also known as 904L steel – Circa 1970

Fast forward three decades, the Ploprof made its comeback in 2009, with the Seamaster Ploprof 1200M, followed by a new edition in 2016. The Seamaster Ploprof 1200M features outsized dimensions and quirky design as the original while incorporating a number of evolutions. As of June 2023, the 3 references listed on the Omega website feature a grade 2 titanium case with dimensions of 55mm x 48mm. As the name suggests, these are water resistance to 1,200m. Unlike the original model, the watch is now fitted with a helium-relief valve.

The new 2023 Ploprof

The celebration of the 75th anniversary of the Seamaster now provides the opportunity to present a new generation Ploprof, with a new case generation. With it, we are going closer to the dimensions of the original, meaning a slightly smaller but still imposing 55mm x 45mm watch. Importantly, the monobloc construction is also back. This means that we no longer have a see-through case back. Instead, the monobloc case is emblazoned with the Seamaster 75th anniversary commemorative logo, a trident-bearing Poseidon with 2 seahorses. The water resistance is still rated 1200m / 4000 ft with a screw-down crown and a Helium Relief Valve.

The angular bunker-like Ploprof case is no longer in titanium but once again in a special steel alloy. Just like the Omega Seamaster Planet Ocean Ultra Deep, it is made of O-MegaSteel. This nickel-free alloy aims at bringing better hypoallergenic properties, as well as enhanced resistance to corrosion. Where 316L steel is given for 200-250 MPa (depending on the alloys), 904L is given for 220 MPa, the O-MegaSteel strength is announced for 560 MPa. Its hardness is of 300 HV versus 200 HV for 316L steel or 175 HV for 904L steel.

In line with the Seamaster 75th anniversary collection colorway, this new Ploprof comes in a sober and elegant blue attire. Its gradient sun-brushed “summer” blue dial features thin, elongated and legible markers. The oversized losange minute hand allows you to monitor dive times at a glance. The hands and indexes are filled with with a unique light blue Super-LumiNova. The bi-directional rotating bezel features a sapphire insert varnished blue on the back. The diving scale beneath and the bezel locking pusher are also rendered in blue.

Inside the watch, no surprise as we have the Omega calibre 8912, a no-date version of the Metas-certified calibre 8900. As such, it comes with the full package of Omega’s technologies: a coaxial escapement, a free-sprung balance, a silicon Si14 balance spring and a magnetic resistance to 15,000 gauss. Its frequency is of 3.5Hz and its two barrels mounted in series provide 60-hours of operation. The “time zone” function allows for practical adjustments in one-hour increments without stopping the watch.

The Omega Seamaster Ploprof 75th anniversary is presented on a blue rubber strap using the iconic “isofrane” ladder design and closed by a steel pin buckle. 

All in all, this new Ploprof might very well be the greatest news in the Seamaster 75th anniversary collection. It is a polarizing design and it surely goes against the current trend for smaller watches, but the Ploprof has never been for the faint of heart. It is a professional instrument we like for what it is! Price is set at EUR 15,300 or CHF 13,500. The watch is not a limited edition. And if all other 7 models of the Seamaster 75th anniversary collection are available immediately, this new Ploprof will only be delivered as of November 2023. 

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4 responses

  1. It’s a shame this is going to take so long to come to market. With summer just now arriving in the northern hemisphere, it makes perfect sense to release the Ploprof immediately. Sad to say, but I will probably have lost my itch for this piece come November.

  2. 5mm x 45mm x 15.5mm is obviously a typo. This one is interesting. An HEV is redundant for a watch with a monobloc case, though. Indicating the movement’s name on the case back is silly, but it’s no big deal. Will there be a bracelet version?

  3. Anonymous: The reason for the HE valve is because ISO diving regulations require it regardless of the type of case, so. Omega had to add it.


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