What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
The Seiko Prospex SLA043J1 and SPB183J1 are both blue, 200 m water-resistant limited editions from Seiko’s 2020 diver’s-watch anniversary releases—but they reinterpret different watches. The SLA043J1 re-creates Seiko’s 1965 diver with a 39.9 mm case and caliber 8L35. The SPB183J1 modernizes the 1970 asymmetrical diver, pairing a 42.7 mm case and protected 4 o’clock crown with caliber 6R35 and its stated 70-hour power reserve.
How do the SLA043J1 and SPB183J1 differ?
The key distinction is their design lineage, followed by their size, movement, case construction, and release-era price positioning. They are not simply two sizes or price grades of the same design: Seiko based the SLA043J1 on its 1965 diver and the SPB183J1 on its 1970 asymmetrical diver.
| Specification | SLA043J1 | SPB183J1 |
|---|---|---|
| Design inspiration | Re-creation of Seiko’s 1965 diver | Modern reinterpretation of Seiko’s 1970 asymmetrical diver |
| Case shape | 39.9 mm diameter; conventional round diver case | 42.7 mm diameter; asymmetrical case with crown at 4 o’clock |
| Thickness and length | 14.1 mm thick; 47.9 mm long, reported by Monochrome Watches | 13.2 mm thick; 46.6 mm lug-to-lug, listed by Seiko Philippines Official Store |
| Movement and stated reserve | Caliber 8L35; 50 hours, reported by Monochrome Watches | Caliber 6R35; approximately 70 hours, listed by Seiko Philippines Official Store |
| Case material | Ever-Brilliant Steel | Super-hard-coated steel |
| Crystal | Box-shaped sapphire | Dual-curved sapphire with inner anti-reflective coating |
| Water resistance | 200 m | 200 m diver’s water resistance |
| Limited-edition quantity | 1,700 pieces | 5,500 pieces |
| Release-era retail price | EUR 5,050, reported by Monochrome Watches in 2021 | EUR 1,525, reported by Monochrome Watches in 2021 |
Specifications and measurements come from different sources: Seiko’s official announcement, Monochrome’s 2021 review, and the Seiko Philippines Official Store listing. In particular, the SLA043J1’s 47.9 mm length and the SPB183J1’s 46.6 mm lug-to-lug figure are reported labels from their respective sources, so they are useful context rather than a guaranteed like-for-like measurement method. The 2021 euro prices are historical launch-era figures, not current resale valuations.
Which design lineage suits you?
SLA043J1: a 1965-inspired re-creation
The SLA043J1 follows the design of Seiko’s 1965 diver, the company’s first diver’s watch. Its rounder, more compact-looking proportions and box-shaped sapphire give it a different visual character from the angular, asymmetrical SPB183J1. Seiko says the caliber 8L35 was developed expressly for diver’s watches and is assembled by hand at the Shizukuishi Watch Studio. A dolphin emblem appears on the case back.
#1 Best Overall
- STUNNING BLUE DIAL: this rugged sports watch features a beautiful Manta Ray-patterned blue dial, with Lumibrite dial indicator hands and markers for low light and a magnified day/date calendar
- BLACK BEZEL: this versatile men’s watch features a black ceramic unidirectional bezel with distinctive scalloped edging, for elapsed timing
- AUTOMATIC & MANUAL: SRPF77 automatic watches for men power up with your natural movements, and feature the ability to wind manually, with 41 hours of reserve power
- WATER-RESISTANT: these rugged stainless steel dive watches for men feature a deep blue silicone strap and are both stylish and robust, following ISO standards for scuba, and are water-resistant to 200 meters
- 4R36 CALIBER: equipped with the reliable 4R36 caliber, these precise men’s wrist watches ensure the most accurate timekeeping
SPB183J1: a 1970-inspired reinterpretation
The SPB183J1 takes its cues from Seiko’s 1970 diver. Its asymmetrical case extends around the crown at 4 o’clock, a defining feature that separates it from the SLA043J1. The blue dial carries a gilt “Diver’s 200m” inscription, as noted by Monochrome Watches. Seiko specifies a Zaratsu-polished upper bezel surface.
How do the case dimensions affect fit?
The SLA043J1 is narrower by diameter: Monochrome reports 39.9 mm across and 14.1 mm thick, with a 47.9 mm length. The Seiko Philippines listing gives the SPB183J1 as 42.7 mm across, 13.2 mm thick, and 46.6 mm lug-to-lug. That means the larger-diameter SPB183J1 is actually listed as thinner, while its reported lug-to-lug span is shorter than the SLA043J1’s reported length. Because the figures are presented differently and come from different sources, try both on if fit is a deciding factor.
Monochrome’s reviewer described the SLA043J1’s proportions as restrained on wrist and found the SPB183J1’s 4 o’clock crown comfortable. Those are that reviewer’s hands-on impressions, not a guarantee that either watch will fit or feel the same on every wrist.
Rank #2
- WATER-RESISTANT: these water-resistant men's dive watches are ISO scuba-approved to depths of 200 meters
- AUTOMATIC: these self-winding, automatic men's watches are powered by your movement, with a power reserve of 41 hours
- STAINLESS STEEL: features a durable 43.8mm stainless steel watch case and bracelet.
- LUMIBRITE DISPLAY: this men's automatic watch features a highly-legible display with LumiBrite hands and markers
- 4R35 CALIBER: equipped with the reliable caliber 4R35 automatic movement, this accurate men's watch keeps precise time
What do the movements and materials offer?
SLA043J1: caliber 8L35 and Ever-Brilliant Steel
Seiko specifies the 8L35, a movement developed for diver’s watches and hand-assembled at Shizukuishi Watch Studio. Monochrome reports a 50-hour power reserve. The case uses Ever-Brilliant Steel, and its box-shaped sapphire crystal distinguishes its construction from the SPB183J1’s dual-curved crystal.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchPC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11SPB183J1: caliber 6R35 and coated steel
The SPB183J1 uses caliber 6R35, for which Seiko states an approximately 70-hour power reserve. The regional Seiko Philippines listing gives an accuracy specification of +25/-15 seconds per day, automatic and manual winding, and 24 jewels. Those figures describe the listed specification; they do not establish how accurately every individual watch will run.
Its case is steel with a super-hard coating. The dual-curved sapphire crystal has an inner anti-reflective coating. The Seiko Philippines listing also specifies a screw-down crown and a three-fold clasp with secure lock and extender.
Rank #3
- Iconic Promaster watches with advanced functions designed to venture to the deepest depths.
- 3 Hand, Date
- Silver-Tone Stainless Steel
- Luminous Hands and Markers and Anti-Reflective Mineral Crystal
- Featuring our Eco-Drive technology – powered by light, any light. 200 Meters Water Resistant and 5 Year Limited Warranty
How do the straps and water-resistance features compare?
Both models are rated to 200 m water resistance, and Seiko’s anniversary announcement says each special box includes an additional blue silicone strap. The SLA043J1 is described by Monochrome with a black silicone strap and the extra blue strap. For the SPB183J1, Seiko Philippines lists a bracelet, clasp extender for a full wetsuit, and an additional silicone strap. That regional listing specifies 20 mm between the lugs.
Both are presented as diver’s watches, but the shared 200 m rating does not make their wearing setups identical: the SPB183J1’s listed bracelet extender is a specific practical feature, while the SLA043J1’s reported setup centers on silicone straps.
How limited were the anniversary editions?
Seiko announced the SLA043J1 as limited to 1,700 pieces and the SPB183J1 as limited to 5,500 pieces, with both announced for November 2020 availability. The smaller production number makes the SLA043J1 the scarcer edition by announced quantity; it does not, by itself, establish present-day market value or availability.
Rank #4
- KHAKI GREEN DIAL: this rugged sports watch features a khaki green dial patterned to mirror the shape of the bezel’s edge, with Lumibrite dial indicator hands and markers for low light and a magnified day/date calendar
- BLACK BEZEL: this versatile men’s watch features a black ceramic unidirectional bezel with distinctive scalloped edging, for elapsed timing
- AUTOMATIC & MANUAL: SRPE05 automatic watches for men power up with your natural movements, and feature the ability to wind manually, with 41 hours of reserve power
- WATER-RESISTANT: these rugged stainless steel dive watches for men feature a khaki green silicon strap, and are both stylish and robust, following ISO standards for scuba, and are water-resistant to 200 meters
- 4R36 CALIBER: equipped with the reliable 4R36 caliber, these precise men’s wrist watches ensure the most accurate timekeeping
Is the SLA043J1 or SPB183J1 the better value?
The launch pricing placed the watches far apart: Monochrome reported EUR 5,050 for the SLA043J1 and EUR 1,525 for the SPB183J1 in 2021. Those are release-era prices, not current offers. The difference in price accompanies substantial differences in movement, case steel, design, and edition size, so the historical figures alone cannot establish which is a better buy today.
- Choose the SLA043J1 if the 1965 design, smaller diameter, Ever-Brilliant Steel, and caliber 8L35 are the features that matter most to you.
- Choose the SPB183J1 if you prefer the asymmetrical 1970 design, 4 o’clock crown, longer stated reserve, dual-curved sapphire, or bracelet extender.
For a current purchase comparison, check region-specific listings and compare condition, provenance, and seller reliability. The Seiko Philippines Official Store listing showed the SPB183J1 as sold out when accessed in 2026; that status applies to that regional page at that time, not to global inventory.
Quick Recap
Sources
- Seiko Watch Corporation, “SEIKO DIVER’S WATCH 55th Anniversary Limited Editions”
- Santiago Tejedor, Monochrome Watches, “Seiko Prospex Diver’s 55th Anniversary SLA043J1 and SPB183J1,” February 9, 2021
- Seiko Philippines Official Store, “Purchase Prospex SPB183J1 Seiko Diver’s Watch 55th Anniversary Limited Edition”
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Recommended Free Tools
