Borna Boschunjak
Seiko is a watch brand that is a true watch fan. So, to track so many important references, Easter eggs, and sub-brands of Seiko Corp., you would have already become an enthusiastic person by the time you remember them all. Today, this topic offers the current 62-squares, the 60th anniversary of the first Seiko Dive Watch in 1965, but strangely enough, this celebration headline release refers to a 1968 watch instead. Of course, I’m talking about refs. 6159 with its huge monoblock case and high-beat movement that continues ultimately to stimulate the marinade master line. The Seiko Marinemaster Professional SLA081 is the latest and largest member of its collection: the sports titanium monoblock construction, an innovative bezel retention system, 600 meters water resistance, and the epic Seiko movement. It may not look like a 62 square, but it certainly feels like a valuable successor.
case
Let’s start with that case as it will be a critical feature of SLA081. Get the size that’s not intrusive first. Width 45.4mm, thickness 16mm, and Lug-to-Lug 50.4mm. We often point out that diameter is not all of all sizing, but in this case this is just as good as being a proper beast on the wrist. Here is the “but” and that is the material of the titanium case. This watch is by no means lightweight, but if it was made into steel, I can’t imagine how much it weighs.
The coolest part is definitely the one-piece case construction, referring to the ultra-collectable ref. 6159 From the late 60s to the early 70s. By removing potential access points via caseback, Seiko must install movement and dial from the front of the watch. You will also notice that the SLA081 has 600 meters of water resistance, but does not have a helium escape valve. Just like the titanium case material, here SLA081 takes inspiration from another Seiko legend of 1975. Alongside the new case material, the tuna has introduced a special L-gasket that prevents helium from entering the watch first.
You will also notice that the construction of the case has added complexity with black protruding under the lug and bezel. This is Seiko’s special bezel retention development, which simply removes four screws into the case back, rather than attaching the bezel directly to the case as usual, allowing for cleaning.
And while it’s not a material that Seiko often uses, the company’s expertise in titanium finishing is clear. The brushing and polishing are very well done, with a rapid transition between the different facets, the most obvious, along the sides of the case. It is a particularly eye-catching polishing, as it was able to extract an impressive amount of gloss from a very dull material.
Dial
The dial is just as unique as the case, but it goes a little more subtle. At first glance, it may seem a bit strange for such an expensive watch to choose simple pad printing for indexes. The truth is much cooler than that. The Marinemaster SLA081 has an index that is actually part of the dial, extruded from a single white space into a convex shape. As a result, the dial is better protected from shocks, as the index may fall, but still has a 3D effect.
Seiko further emphasized the three dimensions, covering the entire dial with a thick layer of transparent lacquer, which is at the same height as Rehaut. As a result, the dial surface itself is flat, but the texture pattern below shifts and reflects like a dial we saw previously, aided by the gradient abyss blue finish. I know this is a watch made to meet the demands of deep sea diving, but I was able to easily see this dial on the dressy Grand Seico.
bracelet
A common competition for many Seiko fans is their bracelet, which certainly can feel a bit of an afterthought. Seiko is clearly attracting attention as the latest release carefully considers this element of the watch, and the Marinemaster Professional SLA081 is similar. The multi-link multi-finish bracelet is extremely comfortable thanks to the rounded links, tapering from the wide range of lugs and not feeling overwhelming.
The clasp is still bulky, but is finished like the rest of the bracelet, providing diver extensions. It’s not as seamless as some tool micro adjustments, but it’s certainly a utilitarian worthy of the rest of the watch.
Movement
Here we can’t even talk about hiding behind the caseback of the screw-down caseback. Not just one, Seiko still includes a medallion with its distinctive wave insignia. The 8L45 is a new one in the Seiko catalogue and also appears in the new King Seiko Vanuck Line, and comes from the Grand Seiko 9S65/9S68 line. It has a 72-hour power reserve and is a huge increase from its 8L35/9S55 predecessor thanks to its thin, long main spring, but unlike the original High Beat Seiko professional diver, it beating at 4Hz.
verdict
If more persuasiveness is needed, SLA081 will be field tested as part of the Arctic Research Programme by the Japanese Agency for Japanese Ocean Geoscience and Technology (I see why the acronym JamStec is preferred). Seiko and Jamstec have numerous watches that accompany proper deep diving from 600 meters to 3,000 meters in 1983 to 3,000 meters in 2014. The 2014 tuna references SBBN013 and SBDX011 were randomly selected from the production line and survived only up to 1,000 meters, but were rated at 1,000 meters up to 3,284 meters. 4,299 meters for automatic variants.
Seiko Marinemaster sla081 should be a complete antithesis of what I personally find cool on watches. It’s a ridiculous, 38mm vintage piece with questionable reliability. The dial is incredible, and the materials and construction of the case are a proper throwback to Seiko’s past legends without feeling overly gimmicky. But with the SLA081 proportion in mind, it’s easy to see overwhelming our small fork appendages, but with such impressive spec sheets and their appearance, I feel that the 600-piece limited edition will pop out of the display cabinet when it’s released in July 2025.
Seiko Prospex Marinemaster Professional 60th Anniversary SLA081 Price and Availability
The Seiko Prospex Marinemaster Professional SLA081 is a limited edition of 600 units and is available in July 2025. Price: USD 4,600, USD 7,200
Brand Seiko Model Prospex Marinemaster Professional Seiko Diver’s Watch 60th Anniversary Limited Edition Reference SLA081 Case Dimension 45.4mm(D) x 16mm(T) x 50.4mm(LTL) Case Material Titanium and DLC Stainless Steel Bezel Insert Water Resistant 600m, Screw Front Diamond Pep 5 Link Titanium Bracelet, Folding Security Clasp Movement 8L45, In-house, Auto Power Reserve 72 Hours Features Limited Date Availability, July 2025 Release Date Price US $4,600
$7,200
Trends in the store
Please visit the shop
