Watches from the Seiko Marinemaster series meet the demands of professional divers. Top watches can even withstand the pressure at depths of 3000 m. The workmanship is of the highest quality and on par with Swiss luxury watches.
Models from the Seiko Marinemaster line are expert diving watches that tick reliably even under extreme conditions. Top models from the series are water resistant to 1000 m (100 bar), making them ideal for the professional diver. In 2014, the Marinemaster Professional 1000m was even attached to the outside of an unmanned research submarine and reached depths of 3000 m without any problems.
Features of these watches include large cases, readable dials, brightly glowing hands and index markers, and a crown position at 4 o'clock. The Japanese manufacturer Seiko uses very precise quartz movements or robust automatic calibers such as the 8L35, which is particularly reliable and long lasting. The models of the Seiko Marinemaster series belong to the Prospex collection, which stands for "professional specifications" and includes numerous sports watches fit for professional use.
|Model||Reference number||Price (approx.)||Water Resistance|
|Marinemaster Professional 1000m Diver’s Hi-Beat Limited Edition (700 pieces)||SBEX001||6,400 euros||1,000 m (100 bar)|
|Marinemaster Professional 600m Spring Drive||SBDB011||4,200 euros||600 m (60 bar)|
|Marinemaster Professional 300m Limited Edition (1,000 pieces)||SBDX012||3,500 euros||300 m (30 bar)|
|Marinemaster Professional 1000m||SBDX013||3,400 euros||1,000 m (100 bar)|
|Marinemaster Professional 300m Limited Edition (200 pieces)||SLA015||3,000 euros||300 m (30 bar)|
|Marinemaster Professional 300m||SBDX001||2,700 euros||300 m (30 bar)|
|Marinemaster Professional 300m||SBDX017||2,200 euros||300 m (30 bar)|
Prices for a mint condition Seiko Marinemaster range from about 1,000 euros for a quartz model to around 4,200 euros for a Marinemaster Professional 600m Spring Dive with a new, high-precision escapement system. For Seiko collectors and enthusiasts, the limited special editions are of particular interest. The Prospex Marinemaster 300m with the reference number SBDX012 is one such model and was limited to a run of 1,000 pieces. If you hope to find one of these watches in good condition, you should set aside about 3,500 euros.
Even harder to come by is the Marinemaster Professional 1000m Diver’s Hi-Beat Limited Edition , which was limited to 700 pieces and has the reference number SBEX001. What sets this titanium watch apart is the in-house movement 8L55 with its balance wheel that vibrates at a frequency of 36,000 alterations an hour (A/h). In contrast, the balance wheel of the caliber 8L35, which ticks in many other Marinemasters, vibrates at the more common frequency of 28,800 A/h. At the time of its release, the SBEX001 cost 6,400 euros. These two limited editions were introduced in 2015 in commemoration of the 50th anniversary of Seiko diving watches.
The Seiko Marinemaster 300 serves as a good entry point into the Marinemaster series. In terms of appearance, this watch is reminiscent of the popular Seiko Sumo largely due to its 44-mm stainless steel case, diving bezel, and crown at 4 o'clock. The Sumo is also water resistant to 300 m (30 bar), but the two watches differ in their details. The caliber 6R15 ticks in the Sumo, whereas the Marinemaster 300 is powered by the higher-quality and more precise 8L35. The design of the numerals and minute markers on the unidirectional bezels of these watches also differs.
If you examine the cases closely, you'll notice that the backs of these watches are not the same. The Sumo has a conventional screw-down case back, whereas the Marinemaster 300 has a Monobloc case, which can only be opened from the front. This means that the inner mechanics of the watch can only be accessed if one removes the bezel, watch glass, and the dial and hands. The Japanese manufacturer uses its in-house Hardlex crystal in both models, which is more robust than conventional mineral glass, but not as hard as sapphire glass. The advantage of the Monobloc case is that helium molecules cannot infiltrate the watch, making it suitable for professional saturation diving. Both models bear the tsunami logo on their case backs, as is typical of Seiko diving watches, and have excellent finishing. The high quality satin-brushed and polished surfaces is on par with Swiss luxury watches.
You can buy a Seiko Marinemaster 300 with reference number SBDX001 in mint condition for about 2,700 euros. The model with reference number SBDX017 is easier to find and can be bought for around 2,200 euros. A Seiko Sumo with reference number SBDC031 is significantly more affordable, selling for around 450 euros.
If 300 m (30 bar) water resistance is not sufficient for you, you should take a closer look at the Marinemaster Professional 1000m. As its name suggests, this professional diving watch is water resistant to 1000 m (100 bar). In 2014, this model even held up at 3000 m underwater. This kind of resistance to pressure calls for a massive, robust case. Thus, the Marinemaster 1000m with reference number SBDX013 is 48 mm in diameter and 17 mm thick. This large case is reminiscent of a tuna can, which led to the watch's nickname "Tuna".
Even though this timepiece isn't exactly suited to everyday use, it enjoys immense popularity among Seiko fans. The model with reference number SBDX013 has a titanium case with black titanium carbide plating, making it even more durable. It fits on the wrist with a flexible silicon strap and keeps the time with the caliber 8L35, which has a power reserve of 50 hours and is also used in the MM 300. The daily deviation lies between +15 and -10 seconds and is thus not quite on the level of a Swiss chronometer. Seiko uses its proprietary luminescent material LumiBrite on the hands and index markers, making them easily legible in the dark.
For those who are less attracted to a black design, the Seiko Marinemaster Professional 1000m with reference number SBDX014 presents an appealing alternative. This model is identical in construction with the Ref. SBDX013, but distinguishes itself with red-gold elements. In contrast to the MM 300, the SBDX014 and SBDX013 models use sapphire glass to protect the display from outside influences. Sapphire glass is indeed significantly harder and more scratch resistant than Hardlex crystal, but does crack more quickly. Both Marinemaster 1000m models cost about 3,400 euros new.