The dive watch is perhaps one of the most recognisable styles of watches, and it is hard to imagine a watch lover not buying one fairly early in the collecting journey.

Naturally, that often means gravitating towards the familiar names, the ones with decades of established history behind them. For many collectors, those are the starting points.

But there is another way to look at dive watches. The other way around, if I may.

That does not mean dive watches with no history and entirely new development built from the ground up in modern times. Such a thing would be fascinating, but watches like that are understandably hard to come by.

Rather, it means dive watches, or even entire line-ups, that may appear to be all-new developments, but in fact embody a brand’s decades of accumulated experience in continuing to improve and innovate. They are the culmination of know-how built patiently over time. And to me, that is very interesting, perhaps even more so than staying close to the original throughout the years.

Which is why it is rather exciting to see the new “Ushio” Diver Spring Drive U.F.A. from Grand Seiko, a 40mm, all-titanium watch that finally seems to hit the sweet spot from every angle – the right size, the right style, the right material, and the right movement. It is not a watch that screams, but for those familiar with the Seiko family, this is the sort of watch that stirs something almost immediately. There is something deeply moving about that. Allow me to explain why in this review.

The blue dial variant, ref. SLGB023. (Image: Revolution ©)

Signature Seiko-style, but better

Collectors who love Seiko dive watches often appreciate how rugged and practicality-driven they are. The Marine Master, for example, is a large, unapologetic watch, and it works precisely because of that. The same goes for the Tuna.

That spirit has, in many ways, carried through to Grand Seiko, the more refined and elevated expression of the same lineage. Which is why its dive watches have traditionally remained relatively large, often in the 44-47mm range. And in a way, they have sometimes felt caught between two identities. Take the now-discontinued SBGA229 Spring Drive diver, for example. It tried to be both refined and rugged, and while it was still an attractive watch, it never quite felt like the definitive dive watch.

That begins to change with the new Ushio collection.

For the first time, a Grand Seiko dive watch comes in at just around 40mm – 40.8mm to be precise. That alone is a significant shift. It is a far more wearable size for a much wider range of wrists.

And yet, in becoming smaller, it does not lose any of its rugged character. In fact, it feels more resolved. The case carries the signature Grand Seiko angular lugs and sharp bevels, but in a more controlled execution. It is more rugged than the SBGA229, and even the Hi-Beat SBGH229 with a similar case in the current line-up, yet more restrained than the SLGA001. In other words, it lands in a very deliberate middle ground – expressive, but not excessive.

A newly developed case. (Image: Revolution ©)

To complement the angular case, the bezel now features trapezoidal cut-outs for its notches. The spacing is precise and considered, the kind of detail that suggests real attention to proportion and rhythm.

More importantly, the design language continues onto the dial. For the first time, Grand Seiko does not use rounded markers on a dive watch. Instead, it introduces the angular indices associated with the Evolution 9 design language, first seen when the brand introduced its latest generation aesthetic alongside its modern movement architecture. While those markers can feel bold on dressier pieces, they feel entirely natural here.

Which raises the question of why it took so long for this to happen. Now that it has, it feels like a long-awaited alignment of design language and purpose. For many collectors, this may well feel like a point of resolution.

A coherent design language from case to dial. (Image: Revolution ©)

Tidal-patterned dial

It is not common for Grand Seiko to equip its regular-production dive watches with patterned dials, as these are usually reserved for limited editions. One notable example from the past was the SBGA391, released in 2019 during the pre-COVID era, with a green dial featuring a repeating lozenge motif.

Now, however, the regular-production Ushio line introduces a pair of tidal-patterned dials in blue and green, which is welcome news. The surface is made up of horizontal ridges and raised lines, effectively evoking the movement of ocean waves. This effect is further enhanced by Grand Seiko’s meticulous dial finishing process, which involves multiple layers of coloured and transparent lacquer to create a surface that feels almost glazed.

Grand Seiko’s patterned dials are often sublime in person, though at times they can feel slightly dominant. Here, however, the execution feels better integrated. The surrounding dial elements are strong enough that the pattern does not overpower them, instead working in harmony to complete the overall composition.

Layers of lacquer give the wave-patterned dial its rich sheen. (Image: Revolution ©)

Lightweight as a diver’s watch should be

It is also worth noting that the new dive watch is not only smaller, but also constructed entirely in lightweight materials, using the brand’s proprietary high-intensity titanium for both case and bracelet. This makes it a genuinely comfortable everyday diver — almost a desk diver in the best sense.

The clasp has also been upgraded, which is significant, as Grand Seiko clasps have historically been a weak point until recently. Last year, alongside the introduction of the U.F.A. series, the brand unveiled a new micro-adjustment system with a sliding mechanism for fine incremental extension.

This year’s dive watch takes that idea further. It now features an additional on-the-fly extension link, allowing a much larger adjustment range when wearing over a wetsuit or thicker clothing. At this point, it feels as though Grand Seiko’s dive watch clasp has finally reached maturity.

Concluding thoughts

While the Ushio may not be the most headline-grabbing watch at Watches & Wonders 2026, it is arguably one of the most complete. It feels like the culmination of the Seiko family’s more than half a century of dive watch development, distilled into a refined and cohesive form.

It brings Seiko’s tool-watch ethos to a higher level of execution under Grand Seiko, aligning it with the brand’s standards without losing Seiko’s original spirit from the 1960s. The result is a watch that is compelling both visually and conceptually, and for that reason, it deserves close attention.

Tech Specs: “Ushio” Diver Spring Drive U.F.A.
Reference: SLGB023 (blue); SLGB025 (green)
Movement: Cal. 9RB1, automatic, ±20 seconds per year accuracy, 72-hour power reserve
Functions: Hours, minutes, seconds, date, power reserve
Case: 40.8mm x 12.94mm, high-intensity titanium
Strap: High-intensity titanium bracelet