If you’ve spent any time around Grand Seiko fans over the past few years, you’ve probably heard the same request on repeat: make the divers smaller. The brand’s dive watches have been impressive on paper but difficult for a lot of wrists to live with, coming in at 43.8mm and north of that in some cases. At Watches & Wonders 2026, Grand Seiko finally responded. The new SLGB023 and SLGB025 are completely redesigned Evolution 9 divers in blue and green, built around a 40.8mm high-intensity titanium case and powered by a new U.F.A. Spring Drive caliber. It’s a big shift for the collection, and one that’s been a long time coming.
But oooohhh boy, these are pricey. We’ve talked about this on the podcast more than a few times. Grand Seiko’s insistence on oversized dive cases has felt like one of the more puzzling blind spots from a brand that otherwise seems to understand what collectors want. I’m genuinely glad to see them course correct here, even if part of me wonders why it took this long.
The new case measures 12.9mm thick with a 300m depth rating, and the use of titanium keeps weight down in a meaningful way. Construction follows the Evolution 9 design language with angular, multifaceted surfaces that are predominantly brushed but include some of the Zaratsu-polished highlights Grand Seiko is known for. A 120-click unidirectional bezel sits up top with a color-matched ceramic insert in either blue or green. The bezel markings carry over from earlier generations, though the font has been updated to squared numerals that feel more contemporary alongside the Ushio dial pattern.
Speaking of the dials, Grand Seiko has been using the Ushio motif since 2022. The name translates to “tide” in Japanese and references the waters surrounding the archipelago. Both dials feature a rippling texture with a smooth gradient that darkens toward the edges, and the minute track is pushed to the rehaut to give the hour markers as much real estate as possible. At first glance, these look like some of the more legible Grand Seiko diver dials we’ve seen in a while.
The movement inside is the Spring Drive caliber 9RB1, part of the U.F.A. series. It runs 33 jewels, measures 30mm across with a 4.7mm profile, and delivers 72 hours of power reserve. Accuracy is rated at plus or minus 20 seconds per year, which works out to roughly three seconds per month. That’s a number that still catches your attention no matter how many times you see it on a spec sheet.
What stands out most here is how overdue this move feels. Grand Seiko competes in a segment where 40mm titanium divers with serious movement credentials aren’t exactly unheard of, and the brand’s larger cases have been a genuine barrier for potential buyers. Getting the case down to 40.8mm while housing a new Spring Drive caliber is a meaningful step. Pricing is, unfortunately, $12,400.
Now, the question I keep coming back to is whether Grand Seiko will extend this thinking further. A similar approach applied to a more accessible 9F quartz diver (PLEASE!) could open up a whole different conversation. For now, though, this is a welcome move in the right direction. But way too pricey in my eyes.
Co-Founder & Senior Editor
Michael Peñate is an American writer, photographer, and podcaster based in Seattle, Washington. His work typically focuses on the passage of time and the tools we use to connect with that very journey. From aviation to music and travel, his interests span a multitude of disciplines that often intersect with the world of watches – and the obsessive culture behind collecting them.