Monochrome Watches
An online magazine dedicated to fine watches

Seiko Prospex Diver 55th Anniversary SLA043J1 and SPB183J1

Two new models inspired by some of the greatest Seiko dive watches of all time.

| By Brice Goulard | 5 min read |

As already explained in previous articles, Seiko is celebrating the 55th Anniversary of its involvement in dive watches this year. Knowing Seiko, the best word would be “dedication” given the influence of the brand on this category of watches. In March, the brand announced a trilogy of high-end, ultra-performant dive watches inspired by three of its prominent vintage models: the SLA037, 039 and 041, all of which are now available on the market. Seiko now adds a couple of new models to this collection, still inspired by its past, with the references SLA043J1 and SPB183J1.

While the concept of modern dive watches surfaced in 1953, it took a few more years for Seiko to enter the race. However, once it took the plunge, the Japanese brand became one of the main actors with a solid reputation even today. In 1965, the brand released the 62MAS, the watch that laid down the rules for generations of dive watches to come, from accessible pieces to professionally oriented masterpieces. And one thing to keep in mind is the influence Seiko had on the creation of the ISO 6425 standards…

The 1965 Diver’s Re-creation SLA043J1

The first of the two watches to be released today is, once again, inspired by the brand’s earliest dive watch, the 1965 reference 6217-8000/1, also known as the 62MAS. With its automatic movement (calibre 6217A), 150m water-resistance, large (at that time) 37mm case with a mono-bloc shape and dial with oversized markers and hands, it defined what a Seiko diver should be.

Ad – Scroll to continue with article

This isn’t the first time that we see a faithful re-creation of the 62MAS. In 2017, Seiko had the reference SLA017, with a grey dial and vintage-looking elements. Earlier this year, we also had the reference SLA037, identical in many ways to the 017 yet with updates regarding the movement (Hi-Beat), the materials (specific steel alloy) and the colour of its dial, bezel and strap.

The watch you’re looking at here – Ref. SLA043J1 – shares most elements with the two other references mentioned above. As such, its case measures 39.9mm, retains the typical 62MAS shape and is made of Ever-Brilliant Steel (an internal name for 904L steel). There are noticeable differences, though. The case is now entirely brushed (no more polished casebands), the bezel’s insert is black and the strap too, including a different pattern – waffle vs. tropic.

While the dial retains the signature combination of hands and indexes, as well as the grey-blue colour found on all 55th-anniversary watches, the seconds hand is coloured in light blue. Another important difference concerns the movement. The SLA017 featured the calibre 8L35. The SLA037 came with a hi-beat evolution of this movement, the calibre 8L55. The new SLA043J1 returns to the 4Hz calibre 8L35, a movement developed and assembled expressly for diver’s watches at the Shizukuishi Watch Studio, and based on a GS architecture. This concession, however, keeps the price down to EUR 4,800. The SLA043J1 is delivered in a special box with a blue additional strap made of silicone. It is limited to 1,700 pieces and will be available from November 2020.


  • Case: 39.9mm x 14.1mm – 47.9mm lug-to-lug – Ever-Brilliant Steel case – unidirectional bezel with 60-minute insert – box-shaped sapphire crystal – screw-down crown – 200m water-resistance
  • Movement: calibre 8L35, in-house – automatic – 26 jewels – 28,800 vibrations/hours – 50h power reserve – +15 to -10 seconds per day
  • Strap: 2 silicone straps with steel pin-buckle – black and blue
  • Availability: limited to 1,700 pieces –  in stores Nov. 2020
  • Price: EUR 4,800

The 1970 Diver’s Modern Re-interpretation SPB183J1

The second new model in this 55th-anniversary collection – ref. SPB183J1 – is based on the very cool re-interpretation of the ‘Captain Willard’ watch introduced earlier this year under the references SPB151 and SPB153. This watch is based on the Seiko 6105, the so-called Turtle watch. This watch was worn by Naomi Uemura, a famous Japanese explorer, during most of his exploits; reaching the North Pole alone, being the first to descend the Amazon river in a boat… and more. But it is mostly known because it appeared on the wrist of Captain Willard (portrayed by Martin Sheen) in the cult movie Apocalypse Now.

This new take on Willard’s watch is not an exact reproduction – this was done in 2019 with the SLA033 – but more a fairly priced, modernised take on the original concept. As explained in our review here, the 2020 SPB watches have a more contemporary look, with a 42.7mm case in steel with a super-hard coating and solid construction with 200m water-resistance. The bezel has an aluminium insert and the watch is protected by a bevelled sapphire crystal. And of course, the crown is positioned at 4 o’clock. Inside the case is the modern and powerful calibre 4R35, with 3Hz frequency and 70h power reserve.

On this occasion of the 55th anniversary, this Willard reproduction is adapted with a blue bezel and dial combination and a gold-coloured seconds hand. The watch is worn on a stainless steel bracelet with folding clasp and diving extension. A blue silicone strap is also included in the box. This SPB183J1 will be limited to 5,500 pieces, priced at EUR 1,450 and available from November 2020.


  • Case: 42.7mm x 13.2mm – 46.6mm lug-to-lug – stainless steel case with super-hard coating – unidirectional bezel with 60-minute insert – curved sapphire crystal – screw-down crown – 200m water-resistance
  • Movement: calibre 6R35, in-house – automatic – 24 jewels – 21,600 vibrations/hour – 70h power reserve – +25 to -15 seconds per day
  • Bracelet: stainless steel bracelet with three-fold clasp with secure lock, push-button release and extender – blue silicone strap also included
  • Availability: limited to 5,500 pieces, in stores Nov. 2020
  • Price: EUR 1,450

More details at

3 responses

  1. The SLA043J1 looks very refined for a Seiko dive, my skx looks great on the right rubber strap,but will never look as modern and as I said refined as the 43,that being said $185 brand new with shipping and $8 dollars for the soft rubber strap(ebay and took a week of looking off and on to find one that made the grade for looks and softness at any price). So sub 2 hundred for a skx or the refined one shown above. Like I said I love my skx (on the right strap and until you see one presented properly with a strap that compliments the dial and case you can’t see the hidden beauty, hodinkee is a master at putting the right strap on their LE’s as an example of this art).

  2. Forgot to say the strap on the “refined one “( model 43) does not have the right strap,ironically. Maybe because it reflects the vintage vibe ahead of pairing with a better strap ? Don’t know, but like I said , it’s an art, not a science.

  3. Seiko need to step up a bit more with the SLA models.

    For one, they need better marketed regulation at this price. Yeah, I realize they run well within COSC accuracy in the real world – an acquaintance who recently picked up the Hi-Beat 037 claims it keeps better time than his Sea Dweller, basically staying dead-on throughout most days – but the fact that Seiko don’t put this down on paper implies less than exacting standards with movement adjustment to the WIS/WUS crowd.

    Secondly; warranty and service intervals. Seiko’s warranty range varies by country. In some countries it’s 2 years while in others it’s 3 years. Maybe a handful of countries with 5 years (Australia is the only one I know of) provided you buy at the local inflated AD prices. Shockingly, the supposedly much desired Japanese domestic market (JDM) variants only come with a local 1 year warranty. What’s up with that?! Either standardize a 5 year warranty for these models worldwide or go home, Seiko.

    Thirdly, they need to lose this Limited Edition fetish, or they’ll risk cheapening their brand to Omega levels. I heard they recently hired some big head of marketing from Omega. I wonder if that’s the reason. One can only hope they end this nonsense after this anniversary year.

    It’s a bit sad, because in all other aspects, based on what I’ve seen with other SLA models, the 017 and 037 in particular, these watches are the bees knees. in terms of finishing, aesthetics and general “ingot-like” feel, I personally think they’re better than what Rolex and Omega offer. Seiko just need to round off the whole package.

    As for the other LE blue Willard announced; Well, let’s just say I’m even more glad I got the green version. Matter of personal opinion, obviously. The blue just doesn’t work for me like it does on the SLA. That and I just don’t rate Seiko’s bracelets (not even those on Grand Seikos) all that highly.

Leave a Reply