In the world of luxury watches, Grand Seiko stands out for blending the familiar Japanese craftsmanship with precision timekeeping to create some of the finest timepieces available today. This pursuit of excellence is especially evident in Grand Seiko’s diver watch offerings, engineered for utmost performance even at remarkable depths.

The SBGH257 is a shining example of Grand Seiko’s diving watch achievements. Sporting an impressive set of features encased in the brand’s signature elegant yet robust stainless steel case, this exceptional timepiece represents the pinnacle of dive watch technology and design. In this article we take a closer look at this dive watch, and we will also give you some ideas in case you want to build a homage watch to this outstanding timepiece.


Seiko Divers

Source: Monochrome Watches


With roots tracing back to the 1960s, Seiko’s expertise in dive watches is among the best in the industry. Every single component is thoughtfully engineered to withstand the crushing pressures of deep sea diving, from the high-grade stainless steel case to the premium mechanical movement.

The brand’s diving watches easily meet all ISO 6425 standards thanks to innovations like the Dual Impulse Escapement, delivering precision timing down to -3/+5 seconds per day along with exceptional 200m water resistance. These watches seamlessly blend utility and elegance, making them not only reliable tools for divers but also exceptional timepieces for watch enthusiasts.


The SBGH257

Source: Seiko


Debuting in 2017, the SBGH257 exemplifies these qualities in a stylish yet capable package. It meets professional 600m water resistance ratings through its “high-intensity” titanium case construction and securely screwed matching case back. At 46.9mm, it’s considered an oversized watch even among its diver watch peers, and yet it does not become overbearing to its wearer.

The gently textured dial provides excellent legibility in all conditions, while the large and luminous markers glow bright even in murky depths thanks to Lumibrite technology, making it quite functional during a deep dive. You won’t have problems rotating the bezel as well, thanks to its deep groove that allow for easy operation even with gloves on.

Inside beats Grand Seiko’s calibre 9S85 mechanical movement, assembled by the skilled craftsmen of the Shizukuishi Watch Studio in northern Japan. With 36,000 vibrations per hour and a substantial 55-hour power reserve, this movement delivers incredible accuracy of +5 to -3 seconds per day, worthy of the Grand Seiko name.


Source: Deployant


Upon its release, the exceptional SBGH257 wowed collectors with its suite of features, commanding an initial price of around $6,800 USD. On the pre-owned market today, this rare model fetches upwards of $10,000 in excellent condition, holding value thanks to its robust construction and proven performance as one of Grand Seiko’s flagship divers.

Comparing the SBGH257 to alternatives on the market, it more than holds its own against top-tier Swiss counterparts like the Rolex Sea-Dweller and Tudor Pelagos, with Grand Seiko’s signature styling representing an intriguing alternative.


Source: Monochrome Watches


Even within Grand Seiko’s catalog, the SBGH257 provides an exceptional blend of rugged capability and refined Japanese elegance. It stands shoulder-to-shoulder with the coveted “Snowflake” among Grand Seiko’s most revered and capable models. Simply put, it represents some of the finest achievements in dive watch technology and aesthetics that Grand Seiko offers.


Building an SBGH257 Homage

Of course, we wouldn’t be hyping you up this much if we’re not going to give you the option to make an SBGH257-inspired mod.



In case you missed it, we recently released the NMK944 GS Dive Watch Case, evoking the highly angular design of its muse. It’s almost like a Samurai on steroids, with a polished finish that takes an attempt at mimicking Zaratsu polishing. We designed this homage case to be a tad smaller at 43mm – a small change that will make it even more comfortable to wear for a wider range wrist sizes without taking away from the original oversized design.



It already comes with a matching sterile crown and a brushed stainless steel bracelet for a seamless look. If you want to make it look even closer to the SBGH, you can also pair it with an LX style bezel with its deep and wide grooves. As for the dial, the most homage-y choice is the Oak style dial – the waffle pattern a close match to the model. You can’t go wrong with any of our other dive style dials though; there’s room to be creative and unique!


Wrap Up

For diving enthusiasts seeking the ultimate aquatic companion, the SBGH257 delivers robustness, legibility, and day-to-day accuracy in spades. It rightfully deserves attention alongside the most coveted tool watches of any brand. This Grand Seiko is a modern classic that makes for a great companion from beach to boardroom, and now you can build one at home with our newly released case.

This is just one of our many upcoming releases for namoki November, so keep your eyes peeled! In the next few days, we’ll release even more exciting and intriguing watch cases for you to help elevate your modding to the next level. Whether you’re looking to make a watch modeled after the classics or want to make something nobody else has, namokiMODS has the watch mod parts for you.

Happy modding!

November 12, 2023 — Jeremiah A

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