The Prospex 200m Diver Ref. SBDC051, 053, 101, and 105, are Seiko’s handsome fusion of sleek retro style and modern specifications. Since their debut in 2017, Seiko’s veteran designer Mr. Nobuhiro Kosugi released Seiko’s first-ever professional dive watch, the “62MAS”. Following the Ref. SLA017 which was the most exact modern remake back in 2017, and also the kick-starter of the first 62MAS re-issue design, the SBDC051 (black dial), and 053 (blue dial) have earned their place in this prime collection with nostalgic flair and finesse. Both timepieces offer an unprecedented tribute to Seiko’s first ever diving-ready timepiece released back in 1965. Capturing the same vibes that characterise the phenomenal timepiece that marked the start of Seiko’s journey in professional dive watchmaking, the OG Seiko Ref. 6217-8000. This prehistoric Japanese diver has laid the foundations of design for many of Seiko’s iconic divers after it. With each reissue updated and reinterpreted while still preserving the essence of this timepiece, the OG Seiko has made a name for itself in the dive watch industry and still has a strong following till date.
Throughout the years, new variations like the first PADI collaboration SBDC055 and the Suwa’s 62MAS Reissue Ref. SLA017 have attempted to surpass the SBDC051 and 053, these exquisite second-generation divers are still quintessential in the watch industry. This outstanding pair was later joined by the third generation in 2020, consisting of the SBDC101 and 105. Showing off a vibrant array of colourways, these four models stay true to the timeless essence of Seiko’s original 1965 diver and showcase Seiko’s prowess in dive watchmaking, making conceivable ground-breaking designs a reality.
Perfectly crafted signed case designs and functionality aside, these two generations can be distinguished in terms of external case sizing and other intricate details. As such, the burning question is: which generation is better? Even though both SBDC05Xs and SBDC10Xs are produced inside the same workshop by the same watchmakers, they are far from similar. Hence, by closely comparing the two generations, we seek to unravel the design individuality of each generation consisting of casual skin-divers that we have all come to love. At the end of this article, we conclude that the design and larger size of the discontinued (yes, it’s true) SBDC051 and 053 graces the wrist with a sportier feel as compared to the newer SBDC101 and 103 releases which materialise Seiko’s efforts in paying close attention to their customers’ desires.
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…people came from the skin-diving companies, and they said that we have problems getting a good quality skin-diving watch…
Jack Heuer, 2010
The Seiko 6217-8000, commercially marketed as the 62MAS-010, is the first-ever official dive watch crafted by Seiko. Released in April 1965, this model makes history as the first dive watch with a self-winding movement and is also built with a 150m water resistance that meets the ISO 6425 standard despite the lack of a screw-down crown. Hence, after experimenting with robust water-resistant timepieces like the J12082 Silver Waves model released in 1961, this renowned Japanese watchmaker brings back these exceptional specifications with the Seiko 6217-8000 after four years.
The Seiko 6217-8000 flaunts a skin-diver form, similar to its Swiss counterparts during that era and a depth of 150m which caters to semi-professionals that engage in recreational “skin-diving” just below the water surface without any breathing apparatus. The case shape of the 62MAS fits seamlessly on any wrist because of the strategic lugs design, curving inwards on both ends where they both meet mid case to form a square shape. This watch is fitted with a slim rotating bezel and is equipped with a boxed-shaped acrylic crystal. These features characterise the timepieces of Swiss watch companies during this period where recreational diving was a largely popular hobby.
In fact, the prominence of skin-divers can be traced back to the famous mid 50s Swiss dive watch brands like Aquastar and Squale, widely known for their dressy refined skin divers. These timepieces boast a slimmer case profile even with a screw-down case-back than professional dive watches like the Omega Ploprof and Rolex Sea-Dweller and usually accommodated a sizable winding crown at 3 o’clock without the hindrance of crown guards. Furthermore, the Seiko 6217-8000 is fixed with a double sealed push-pull crown that, surprisingly, is able to guarantee a 150m water resistance effectively. This template form has continued as a staple in the watch industry until today with brands including the dress watchmaker Glashutte Original presenting their own renditions of this functional yet elegant dive watch.
MAS gets its acronym from Seiko-Matic Self-dater which has made a name for itself in watchmaking history. It was one of the pioneers in Seiko to acquire an automatic movement that allows for date setting controlled by its crown which has, since then, become the norm in most timepieces today. However, back in 1965, when Rolex only just released their first Submariner (with date) Ref. 1680, the Swiss dive watches seem to surpass the 62MAS with a better water resistance of 200m, but quickly fall short as they do not allow for quick date-setting. Hence, the 62MAS were well beyond the dive watches of those times and were even chosen by the local Japanese Antarctic Research Exploration team as their go-to tool watches from 1966 to 1969.
The Number “62”
Many would recognize the MAS acronym but not the numerals that come after. In the past, Seiko standardised their watches with nomenclature based on the caliber incorporated as apparent in the naming of the Seiko 6217-8000. This numbering system indicates the movement in its first four numbers and the case number in the next four digits.
The Seiko 6200 series is built with the caliber 6217A which is also found in an extensive range of self-winding watches including the Seikomatic, the Seiko Liners, the Silver Waves and the World-timers. The 12.25 ligne (27.64mm) Caliber 6217A has a beat rate of 18,800 bph, a quick-set date, 26 jewels, sans manual winding and hacking. It was so successful that even after the 6200 series was no longer in production, it was still used in other timepieces from 1964 to 1969.
In the 1960s, the 6200 series were an essential family of timepieces flaunting mechanical movements that were considered exclusive as they powered high-end Seiko watches including the very first automatic Grand Seiko namely the 1966 62GS Ref. 6245-9000 and Ref 6246-9000.
Now, let’s get into the specifications and features of the four reissues.
1. 42.6mm in diameter, 49.50mm lug to lug, 13.8mm thick.
1. 40.5mm in diameter, 47.6mm lug to lug, 13.2mm thick.
2. Entirely done in 316L stainless steel.
2. Equivalent with the 51 and 53
3. Multi-finished in satin-brushed and high polished, coated in Seiko’s proprietary Diashield.
3. Equivalent with the 51 and 53
4. Runs on the 6R15 automatic caliber – 23 jewels, 21,600BPH, power reserve of 50 hours.
4. Runs on the 6R35 automatic caliber – 24 jewels, 21,600BPH, power reserve of 70 hours.
5. 51: Matte black dial / 53: Sunburst blue dial.
5. 101: Silverish sunburst dial 105: Brown sunburst dial.
Made with the same material as the original 62MAS, these four models stay true to the look of the OG Seiko that shook the watch industry 60 years ago. Yet, these models simultaneously ooze a contemporary look, considerably in-tuned with today’s modern market.
The SBDC051 and 053 were considered the kick-starters of Seiko’s high-end vintage reissue wave which had been in line with the Japanese brand’s new (at that time) direction in reviving their legendary divers in years to come. This 62MAS second generation retains all the 62MAS design cues but showcases distinctive traits in execution.
The first batch of 62MAS reissues, consisting of the SBDC051 and 053, stand out with a much-elaborated case construction that goes well with its metal bracelet, especially that of the 051 which offers an excellent fit, more seamless than any bracelets previously produced at the sub $500 to $1000 price point. Both the 05X and 10X cases flaunt a full Zaratsu polishing and distortion-free mirror polishing, finished in a contrasting satin-brush which is separated by bevels featuring a high polish on their sides. This stunning satin finishing on the top surface of the watch case is done flawlessly in a circular manner that mirrors the finishing on the 6217-8000. Also, the additional polished bevelling reveals the commendable attention to detail put into the crafting of the reissues, courtesy of Seiko’s impeccable finishing techniques.
The Zaratsu technique is usually seen on luxurious Grand Seikos or higher-priced limited-edition remakes such as the SLA017 and SBEX009. This daringly spectacular polish results in ritzy and sleek surfaces with impressive multi-finishing and it is quite impossible to find another neo-vintage dive watch within this price range that has similar case finishing qualities. This finishing is then protected with a unique hardening process over the case known as the Seiko DiaShield treatment which is a transparent scratch-resistant coating that allows the 05X and 10X models to be 2-3 times harder than standard 316L stainless steel, which measures 300Hv-700Hv as compared to 200Hv in hardness.
Moving on to the vintage aesthetics which bestows the divers, especially the 10X, with an anachronistic charm. However, the only element that might encroach on the ethos of the 62MAS series is the incorporation of the “Prospex” arrow-head handset on the SBDC05X.
The black and blue steel inserts on the bezel of the 05X boasts proper spaced-out markings that are reminiscent of the original 62MAS while including a glossy update in their aesthetics. This 120-click anti-clockwise rotating bezel operates at great precision with a muted click sound at every rotation, doing away with the typical metallic ticking noises.
The bezel’s shimmering glow is complemented with the glossy metal trimmings that frame the applied hour markers on the dial filled with LumiBrite. Dramatizing the trapezoid-shaped luminous-filled parts of the hour markers on the original 62MAS, the second generation presents hour markers with shiny metal surrounds shaped like trapezoids, an interesting touch to its overall classic dial design.
Another excellent upgrade to the retro skin-divers is the inclusion of a slightly domed sapphire crystal. By fitting the sapphire glass deeper into the case, each timepiece shows off a seamless transition towards its slightly sloping bezel. What’s more, the inclusion of an additional anti-reflective coating applied underneath the glass allows for less distortion from lights and better readability. All these updates highlight the enhanced ruggedness of the new 62MAS Prospex dive watch line consisting of the SBDX101 and 105.
Onto the strap options, the SBDC051 and 101 each comes on a reliable sports bracelet with the iconic triple-lock clasp featuring an ingenious dive suit extension subtly hidden on top. As for the SBDC053 and 105, each model comes on a black silicon rubber strap with different designs and a tang buckle. Personally, I think that this inclusion of rubber strap options is a nice nostalgic touch that harks back to the original 62MAS which also came on silicon straps.
The colourful dial and bezel offerings of the SBDC053 and subsequent dive watch models place more emphasis on design than practicality and bestows these skin-divers with the ideal summer watch aesthetic. With such a vibrant array of timepieces to choose from, customers were spoilt for choice with the blue sunburst dial variant which gives the SBDC053 a slightly more nautical and contemporary feel or the classic matte black variant that flaunts an action-ready, athletic look.
Based on the staple model SBDC051, the 62MAS series updates its 053, 101, and 103 models with greater lustre that grabs attention at a glance. Perhaps this timely enhancement exudes the updated overall appeal of Seiko’s sports Prospex collection.
Not All That Identical, But More Original
Recognised as the third generation of the Seiko 62MAS, the SBDC101 and 105 released in 2020 mark another milestone for the Japanese watchmaker as she unveils yet another extraordinary set of modern 62MAS recreations. In this section, I will compare this new generation with the popular second-generation 62MAS.
First announced in mid-2020, the SBDC101 and 105 are now, tentatively, a sized-down version of the SBDC051 and 053 built stylishly yet with simplicity which is what makes them ever so alluring. Overall, both models are visually similar, except the dial colour tones (which we will get to later), to previous 62MAS models and stand out with their svelte, more delicate and well packaged build.
With a more classic form, this new collection stays true to the vintage diver creed while still boasting a modern build. The first thing to note would be the slight difference in the intricacies of the watch case. If the SBDC051 and 053 are deemed to be the upscaled, multi-chamfered with slim sides skin-divers, then the 101 and 105 would be considered uncomplicated, exuding more anachronistic vintage appeal.
Although their designs seem straightforward, these watch cases are done in the typical “GS” finishing style, a handsome combination of high Zaratsu polishing on the entire case and circular satin-finishing on their top and side surfaces, complemented with a thin mirror-polished bevel across and in between the mid-case. With that, the new 10X 62MAS gets a sturdier look that establishes a more prominent presence on the wrist, as compared to the slender yet sizable 05X variants. As such, the 05X appears to wear slimmer compared to the 10X due to the substantial build of the case. However, the brazen mid-case of the 10X makes this series more reminiscent of the original 6217 variants of 1965.
The result of shaving the SBDC10X case size down is a closer resemblance to the original. Hence, at only 0.6mm larger, the 10X is more similar to the original than the 6217 with its 39.9m diameter, allowing it to better cater to Seiko collectors. Although both generations preserved the impeccable ultra-flat, distortion-free surface polishing, due to the smaller size of the 10X, these satin-brushed finishing have to be more intricate to recreate this athletic sheen, thus resulting in greater finishing refinement.
Nevertheless, the bigger 42mm SBDC05X presents a more slim-looking yet contemporary case form compared to the 10X’s thicker but smaller build. Measuring only 4mm in thickness, the 05X series features a glossier bezel insert that shows off a lustrous gleam as compared to the matte bezel inserts on the new 10Xs which seems broader due its smaller sizing.
The inclusion of a gently sloping bezel and polished grooves allow for the 42mm 62MAS to achieve a slimmer profile. Moreover, the 10X series boasts engraved markers on its bezel, filled with an anonymous white/gold compound which are contrasted with the curved satin-finishing on the matte black bezel insert that enhances readability and gives this model a purposeful tool-watch look.
Despite the difference in size, both sterile screw-down crowns appear identical in sizing. While the 05X flaunts a ritzy mirror-polished surface, the 10X shows off a circular satin-finished that bestows it with a rugged look.
Crafted to the highest standard, the dials of both generations are well balanced and classic. The colour tones of the SBDC101 and 105 exude nostalgia due to their vintage accents that allow these dials to honour Seiko’s subsidiaries back in her heydays. The sophisticated silver accents on the SBDC101 draw the attention of Seiko enthusiasts back to the original Suwa’s version (previous GS-centric subsidiary) of 62MAS and remains in shades of sunburst grey throughout its lifespan. In contrast, the sunburst brown 105 covers the 1967 Daini’s version (previous King Seiko- centric subsidiary) which tends to undergo a tropical-patina with brownish hues that indicate age.
Furthermore, the minute markers on this third-generation model is synonymous with the original 62MAS as they are placed right on the same plane with the less hour plots, giving off warm vintage sentiments that resonate with Seiko dive watch fans.
In contrast, the SBDC05X has minute markers on a concave chapter ring which is placed as a rehaut and sandwiched in between its sapphire crystal and dial plane. Thus, the attention to detail forms a depth in its design which makes this model stand out from the simplicity of vintage dials on the 10X.
Seiko’s expertise in the dial-works and attention to detail are seen in the sunburst variants when their sunburst dial patterns echo the original hues of the sunburst finishing of the OG Seiko which had sported a different dial colour in the past.
Interestingly, Seiko removed the full convex metallic date window frame in all four variants which had been incorporated on the original. Instead, the SBDC05X opted for a painted white arched frame while the SBDX10X forgoes it entirely. Nevertheless, the convex date on both models shows off a matte inner edge that prevents reflections from forming around the date numeral while highlighting the date display. This strategic detail is testament to Seiko’s prowess, careful consideration and immense effort that goes into their design.
Another feature worth considering would be the handsets and applied hour markers. As mentioned before, the SBDC05X showcases a brand-new handset that is synonymous with the Prospex collection from 2017 to 2019. Instead of re-using the exact handset found on their predecessors, second-generation models like the SBDC051 and 053 flaunt a broad arrow hour hand, sword-styled minute hand and a reverse luminous dot for their second hand. Altogether, this newly styled handset is significantly different from previous handsets but still exudes a contemporary retro style.
In contrast, the 2020 10X models live up to the vintage look this time with identical facets hour and minute hands (although different in the number of sides) and a block-shaped luminous tip at the forefront. Best of all, the 105 brown variants feature golden gilt tone markers that match well with this handset which accentuates the overall vintage appeal of this timepiece.
A little titbit: The “OG” hands make appearances on several other Seiko models like the “Captain Willard” Ref. 6105-8110 and the same era though lesser-known “Seahorse” Ref. 6110-8830 (even up to the hour markers).
Yet another worthy mention would be the luminance applications on both generations. The 05X features excellent uninformed use of LumiBrite in each hour marker, accentuated with sleek metallic frames. Additionally, the unconstrained application on 10X models created an overflowing effect, almost as if the luminance was brimming over the frame of each hour marker, resulting in an alluring sense of depth.
Even Up To The Straps
Equally notable, the strap options are distinct from one another and the spotlight falls on the rubber straps found on the SBDC053 and SBDC105. Let’s start off with the metal bracelets. Heavily criticized for the tacky metal bands in the past, the new bracelets found on these Seiko Prospex models boast excellent quality with great attention to detail as compared to entry models like the Seiko Sumos and Samurais.
The bracelet is finished in the typical “GS” style with a combination of satin-brush and mirror-finish with Zaratsu polishing which guarantees a smooth and even surface finishing. These bracelets are so immaculately executed that they far surpass the quality and detail of entry bracelets like the Ref. M021514J0 found on the SRPCS models.
Despite undergoing the same procedures, the sports bracelet M197.B.C on the SBDC101 feels more intricate and a better fit compared to the SBDC051’s M01X331H0. For instance, the solid end-links and links on the 101 have a rounder shape than that of the 051. They are also made smaller in size with no facets on the middle portion. However, the 051 has a substantial appeal due to its long links and faceted-middle section. With that said, both bracelets exude quality and superiority in design and each clasp design is unique at the folding parts; the M01X331H0 shows off a deep engraved “Seiko” logo on the thin folding buckle while the M197213H0 gets a soft lasered logo on a larger fold-lock buckle.
Both rubber strap variants pay tribute to the original (only came on rubber back then) with black silicon rubber straps that are intrinsically distinctive. The SBDC053’s Z20 made out of urethane silicon material, is a genuine take on the classic GL831 accordion rubber strap found on the Ref.6306 Turtle and H558 Seiko “Arnie”. Although the straps have similar designs, the Z20 feels superior due to the durable silicone material used which allows it to be more flexible and softer. The Z20 resolved frustrations and complaints about the GL831 that was easily broken and uncomfortably stiff.
The 2020 105 62MAS model is also paired with another form of silicon rubber strap that is deemed to be Z20’s equivalent which comes in the form of yet another Seiko’s original remake, the XGL-731 strap. Characterised by the “tire tread” patterns on its surface, this strap had been manufactured in the 70s and paired with the Ref.6105-8110 “Captain Willard” Turtle timepieces in the past. With its intricate style, it is no wonder that this design is among the rarest amongst all other rubber straps. Its rareness is because of its pairing on one particular diver with a short production span from 1972 to 1977. Therefore, the 101’s “tire thread” silicon rubber strap is always warmly received by Seiko devotees.
However, despite paying tribute to the original 62MAS, these two rubber straps seem to be considered outliers in terms of the extent of replicating the 62MAS because the OG 6217 allegedly came on either a black tropic rubber or the unique “waffle-pattern” rubber Ref. ZLM01 which was commonly shared among its brethren namely the Ref. 6215-7000 and 6105-8000. But fret not all you loyal collectors after the period-correct case form and straps, Seiko has got us covered with limited edition although slightly pricier models like the 2017 SLA017 (waffle rubber) and the 55th Anniversary SBEX009 (tropic rubber) 62MAS Re-editions.
Another “6” Series Movements
The movements inside both generations are protected by a screw-down case back with the iconic Tsunami emblem, typically embossed in the middle of every Seiko’s Prospex dive watch, a stamp of readiness and quality.
As both generations carry 6R calibers, with subtle differences, this movement marks the revival of Seiko’s “6” series calibers found on sports watches between early 60s and 70s. As mentioned previously (check out our SARX055 article (link the article here)), the higher- end models in the Prospex collection such as the SBDC05X as well as timepieces just before the release of the Marinemasters with the 8L35 GS calibers, run on the 6R15 caliber. It is a hardy, efficient and robust movement that operates at 21,600 bph (3 Hertz), pumped up from 19,800 of the 62 series, with hacking and hand-winding capabilities. It has 23 jewels with a power reserve of 50 hours through a Spron 510 mainspring.
Proven to be reliable and accurate, Seiko went one step further to develop and upgrade the 6R15 engine in 2019 and has released the 6R35 caliber which is characterised by a longer power reserve of 70 hours and an additional jewel on the main plate (also found on “C” and “D” 6R15 variants). The latest 62MAS is powered by this new movement, allowing this remarkable reissued diver to possess the highest modern specifications.
Upon comparison of both calibers side by side, I find the finishing and execution to be identical, all the way from the industrial brushings to the placements of bridges, escapements and gears. Therefore, without the aid of the inscriptions on the winding rotor, it is tough to distinguish one movement from the other.
Therefore, both 6R15 and 6R35 calibers are Seiko’s state-of-the-art engines with proven ruggedness and accuracy for many years of operation and excellent choices for this Japanese brand’s top-tier sports and dress watches like the 62MAS reissues in this case.
Tradition with Innovation
The vintage 6217-8000 is a captivating tool watch that embodies the essence of a classic dive watch and stands out from the many other horological designs in the 60s. It also offers a unique way of appreciating the purest form of a reliable dive watch of that time which is still preserved in authentic reissues today.
It has been more than 50 years since the inauguration of the first professional dive watch, but the 62MAS ethos continues to sensationalise the watch industry till date. Moreover, both generations of reissues are distinct with individualised styles and functionality while still staying true to the original design. Despite their different concepts, with the 05X embodying a combination of utility and excellent aesthetic finishing, while the 10X serves as an accurate throwback of the 62MAS heydays, both flaunt purposeful and robust builds. Adhering to the timeless no-frills look that defines the 62MAS line-up, these timepieces are still highly sought-after until today.
Both re-issues exemplify Seiko’s prowess in manufacturing impeccably built sports watches with impressive finishing quality that enable these timepieces to compete with renowned brands selling at a much higher priced range. Additionally, in emulating the original 62MAS frame, the 05X and 10X guarantees no distractions from the functionality standpoint. All in all, these skin-divers live up to Seiko’s reputation and longstanding expertise in fabricating idiosyncratic, functional tool watches relevant in every season. These 62MAS models exude a similar vibe as the earliest generation of professional divers while keeping up and offering modern designs. The timelessness of these models is proven as even though these timepieces are based on Seiko’s very first dive watch, their overall design is still successful even until now.
While the monochromatic variants of the SBDC051 and 101 each present their own sober take on the 62MAS with toned-down versions of the original design, the multi-coloured variations of these models add vibrance to the genre. This effort reveals the thoughtful consideration and planning done by Seiko to update her collections so as to better cater to the preferences of modern watch collectors.
These outstanding reissues allow for the continuation of vintage dive watch street cred from Seiko. Reimagining classic vintage style in a modern way, the 62MAS reissues have evolved into highly admirable daily “desk” divers with substantial value proposition today.
Ending on a slight queasy note with the recent announcement of the complete discontinuation of the second generation 62MAS reissues, I personally feel that Seiko should continue the production of SBDC05X together with the new SBDX10X variants, instead of discontinuing the second generation to make room for the third. This is because both generations, despite encompassing the same skin-diver appeal, had distinct intentions and goals and I had hopes that these proven models would continue to supplement the sport-chic genre of the 62MAS reissues. But alas, these fantastic watches will be greatly missed.
Luxury watches are not distinguished by stratospheric price points, rather they stand out with timeless sentiments and aesthetics. And these magnificent reissues successfully shower each timepiece with a luxurious aura through a seamless blend of various historical elements with modern sophistication. With each timepiece representing a direct aspect of Seiko’s horological heritage and technicality, these reissues reveal the importance of high quality and trendy designs at reasonable price points which not many brands can offer. Hence, these exquisite reissues showcase this Japanese watchmaker at its twentieth-century best by defining a timeless ethos that encapsulates the 62MAS series which will continue this horological legacy for many years to come.
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