Monochrome Watches
An online magazine dedicated to fine watches

Seiko Diver’s 55th Anniversary, the 1965 “62MAS” Re-Creation SLA037J1

A faithful, fully equipped and high-end re-edition of Seiko's first professional dive watch, the 1965 "62MAS".

| By Brice Goulard | 11 min read |
Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

Seiko’s excellent reputation in the field of dive watches is unquestionable. We’re talking top-tier actor, member of a fine club of influencers that helped shaped what the modern dive watch is today. Yet, on the contrary to some Swiss competitors and their 1953 introductions, Seiko waited for a few more years before taking the plunge. In 1965, the Japanese manufacturer set the tone with an important watch, the “62MAS”, also known as the first professionally oriented dive watch of the brand. This year, Seiko is celebrating 55 years of “professional specifications” (pro-specs… Prospex) dive watches with a trilogy of recreations and today, we go hands-on with “the first”, the Seiko Prospex Diver’s 55th Anniversary 1965 Re-Creation SLA037J1.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

The 1965 Seiko 6217-8000, a.k.a 62MAS

Knowing Seiko’s devotion to the professional-specs dive watch, there’s no escaping the background story about the watch that started it all, the watch that would influence production for 55 years, a watch that actually helped shape the very definition of a modern dive watch – and, for the record, the watch that is the inspiration for today’s reviewed piece.

Ad – Scroll to continue with article

Seiko has made watches for almost every purpose and has been involved in tool watches made for professional divers since 1965. The brand has evolved its concept drastically over the years, with for instance the 6159-7010 Tuna created in 1975 which introduced an innovative, ultra-protected titanium case made for saturation diving. But the one that started it all was launched in 1965 under the reference number 6217-8000, which is mostly known in the collecting community as the 62MAS – MAS being an acronym for “autoMAtic Selfdater”.

Photo by

Being the first, the grandfather of all Seiko dive watches, it had an immense influence on the upcoming production and several of today’s Seiko Prospex Diver’s watches still rely on some of its design elements – hands, bezel, shape case, indexes… It took some time, however, for Seiko to enter the market for professional dive watches. In 1953, Blancpain launched the Fifty-Fathoms, followed by Rolex and its Submariner. In 1957, Omega joined with the Seamaster 300. But as the market for professional dive watches and, as a consequence for recreational dive watches too, was well established, Seiko decided to offer its own take on the concept, with the 62MAS.

Photo by

The specification sheet of the Seiko 62MAS is both impressive for the era and outdated compared to current dive watches. The watch was a 37mm robust piece of steel, with a sharp case and solid shoulders – there’s no denying the instrumental look of the watch. The case has a typical mid-1960s look and a curved profile, as well as the Seiko touch, with a circular-brushed surface. The watch was rated for 150m water-resistance (fairly good back then), had a screwed caseback but the crown wasn’t screwed-down yet. In the same vein, the bezel, already featuring the classic diver’s 60-minute scale, was bidirectional. The 62MAS was powered by the 2.5Hz automatic calibre 6217.

The dial also looks quite familiar as it influenced several generations of Seiko diver’s watches. We find here a grey (often faded on vintage models) dial with a sunray-brushed pattern and oversized rectangular hour markers and hands, chromed and generously filled with radioactive lume. The date is positioned very classically at 3 o’clock, and so is the crown. This is worthy of a mention since the 62MAS is the only Seiko professional dive watch with this configuration – all the upcoming Prospex diver’s watches would feature the crown at 4 o’clock, which became a signature element.

Photo by

While rather unique in design, regarding Seiko’s timeline for dive watches, the 62MAS is packed with elements that would influence 55 years of production. As such, this watch has to be considered of great importance – even though technically speaking, the hi-beat Automatic Diver 300m Ref. 6159-7001 and the 1975 Professional Diver’s 600m “Tuna” Ref. 6159-7010 and all the upcoming “Tuna” watches had greater influence.

I thought it was important to remind you about the 1965 Seiko Diver’s 62MAS ref. 6217-8000, because today’s review will be focussing on a watch that is largely inspired by this very watch.

The Seiko Prospex Diver’s SLA037J1

If you’re a Seiko dive watch enthusiast, this new reference SLA037J1 should feel quite familiar to you… And you’d be right to think so, as it has a lot in common with another 1965-inspired piece, launched at Baselworld 2017, the SLA017. However, the watch that Seiko is launching to celebrate the 55th anniversary of its involvement in dive watches isn’t just a new colour. Certainly, case, dial and bezel feel almost identical, however, there’s more than meets the eye, and that has to do with mechanics and materials.

Seiko Prospex Diver SLA017 Recreation 62Mas - Top 10 Baselworld 2017
The 2017 62MAS Re-Creation, the ref. SLA017. Not much different from today’s SLA037J1, at first…

Design-wise, there can be no doubts concerning the immediate filiation between the original 62MAS and its modern recreation. Visually, most details have been reutilized, providing solid vintage-inspired content. Most elements, if not 100% accurate, are at least very close in shape and design, as well as in their position. But here, you could argue that this isn’t different from the SLA017, and rightly so. Thus, we have to go deeper into the details to understand what’s unique about this 62MAS-inspired SLA037J1.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1
A subtle evolution, but if you look into the details, you’ll see that it goes beyond just a new colour.

Case and design

Shapes and design are one thing, proportions are another. This is where this recreation might record the largest evolution over the vintage model. The vintage watch was not small by any means… back in the 1960s. At 37mm, it was on the large side and still is respectable today. Yet, the 2020s call for larger watches and this new SLA037J1 has grown slightly, but not unreasonably. The case is “only” 39.9mm, making it comfortable on the wrist, compact (lug-to-lug is just below 48mm) and still infused with some retro feelings. The case is not thin, however, at 14.7mm but the ultra-domed sapphire crystal is mostly responsible for that.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

When it comes to the case, the dial or the hands, the SLA037J1 is almost in Grand Seiko territory.

The overall shape of the 62MAS has been respected, with robust integrated lugs, sharp angles and straight flanks. The top surface of the case has a circular-brushed finish, while the sides are polished – and yes, they have been executed thanks to Grand Seiko’s beloved Zaratsu “distortion-free” technique, resulting in a very precise mirror finish. This is where this 1965 Re-Creation surprises… It might look like a purpose-built instrument but it is beautifully executed… This is a deliberate choice by Seiko, which has opted for a high-end positioning of this collector-oriented piece.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

Regarding the case, the material chosen is also uncommon. None of your classic 316L stainless steel here, but Seiko’s own “Ever-Brilliant Steel.” This alloy benefits from more brilliance and a whiter hue, which is further enhanced with the Zaratsu polishing. It is also more corrosion-resistant than traditional steel, which also explains its use on a dive watch.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

On the contrary to the 62MAS, this SLA037J1 Re-Creation employs contemporary solutions to make it a vintage-inspired but modernly equipped dive watch. Following the ISO standards, the bezel is unidirectional. It still features a fully graduated diving scale, applied on a glossy metallic insert with a luminous dot at 12 o’clock. The bezel has a firm, pleasant click when operated. In the same vein, to guarantee the 200m / 20 ATM water-resistance, the crown screws-down, just like the plain caseback (decorated, just like the old model, with a dolphin).

Dial and hands

While the 2017 ref. SLA017 played on the vintage trend with a grey, slightly faded dial that echoed the original 1965 watch, this 2020 edition of the 62MAS takes some liberties with colours. Like its two siblings in the 55th-anniversary collection, this SLA037J1 has a blue-grey dial, a discreet colour that suits the overall concept well and adds a slight dose of modernity and originality to this piece. The dial is lightly brushed, offering reflections and playing with the ambient light.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

Hands and indexes are identical to the 62MAS in shape and positioning, and to the 2017 version in execution. The applied markers are large, rounded-rectangles with a polished surface which contrasts well with the blue background. The markers are generously filled with Lumibrite, Seiko’s own luminous material. To match the markers, the date has a metallic frame and its presence is justified here. The hands are also faithful to the original watch, with the same rectangular shape, although the execution is far more sophisticated.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

Just like Grand Seiko watches, the hands of the SLA037J1 have multiple facets, with large bevels on the sides and a mirror-polished top surface. Not only is this solution very pleasant to the eye and shows attention to details, but it also facilitates time reading as the hands stand out from the blue background.

Inscriptions on the dial pay tribute to the 62MAS too, with the “Diashock” mention at 6 o’clock, next to the jewel count. But here, you’ll notice two things: “HI-BEAT” and “37 Jewels”… and that is a pretty clear indication that inside the case there isn’t a standard movement.


Regarding the specifications of this watch, the real novelty is inside the case. Instead of the calibre 8L35, a classic 4Hz movement, found in the SLA017, the 2020 version of this watch is equipped with a higher-end, hi-beat calibre, the 8L55. What is this movement? To make it simple, it is a non-Grand Seiko version of the Calibre 9S85, well-known to us and used as a base for most hi-beat automatic Grand Seiko watches.

The 8L55 is mechanically identical to its Grand Seiko counterpart and was developed for top-tier Seiko dive watches. The gear train, kinetic chain, winding system and regulating organ are the same, so is the number of jewels, the 5Hz frequency (36,000 vibrations/hour) and the 55-hour power reserve. It also retains high-tech features, such as a “Spron 610” alloy (for the hairspring) and parts manufactured by MEMS technology (escape wheel and pallet forks).

Compared to the Grand Seiko version, the differences are mostly on the decoration of the plates and bridges – even though the 8L55 is already pretty well decorated – and how the movement is adjusted. Seiko announces a +15/-10 seconds/day accuracy (compared to +5/-3 s/d for Grand Seiko), which is known to be on the pessimistic side of things. So, even though not as high-end as what you’ll find in a Grand Seiko watch, the 8L55 movement of the SLA037J1 is already a fine piece of watchmaking.


The new Prospex Diver’s 55th Anniversary 1965 Re-Creation SLA037J1 also comes with a fresh strap. While the SLA017 came with a thick, quite bold waffle-like and glossy silicone (a real dust magnet…), Seiko has opted for something a bit softer and more elegant for its new watch.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

The new strap is still made of silicone, but now with a matte finish, a thinner profile and a tropic-like pattern, which suits the 1960s style of the watch. It comes in blue to match the dial and features a steel pin buckle as well as a brushed and bevelled steel holder, engraved with Seiko. The strap feels comfortable straight out of the box.

Price, thoughts and availability

The Seiko Prospex Diver’s 55th Anniversary 1965 Re-Creation SLA037J1 will be a limited edition of 1,100 pieces, available worldwide July 2020. It will also be included in a special commemorative box with the two other 55th-anniversary re-creations, available in 100 examples in May 2020.

Seiko Prospex Divers 55th Anniversary 1965 Re-Creation SLA037J1

Regarding the price, I’m not going to deny the fact that this SLA037J1 is a costly watch, especially since it has Seiko printed on its dial. At EUR 6,500, it is clearly in Grand Seiko territory. However… disregarding the design, which is clearly Prospex-oriented, the 1965 Re-Creation has more in common with Grand Seiko watches than with a Samurai or a Turtle watch. The material used for the case is impressive and offers a superb lustre, its finishing (with Zaratsu polishing) is on par with GS models, the movement is basically a diver-oriented version of what you’ll find in a Hi-Beat Grand Seiko – with less decoration and a different adjustment process. So yes, this is a high price for a Seiko, but this is also a high-end piece that can easily compete with top-tier Swiss brands.

More details to be found at

4 responses

  1. Nice review, thank you!
    I am a big seiko fan but the price is eye watering, there are other limited editions I would consider before this one. Second hand prices are quite soft for all their reissues, which is great for seiko aficionados.

  2. The issue, while i’m a massive Seiko fan and collector is that Seiko like with the SLA033 they will release a cheap version of this and also honestly at that price point you’re now into sea Q range or Tudor… so I’m not sure.

  3. I’m sure. I’ll wait for the 6R35 version without any hesitation.

Leave a Reply