Grand Seiko Unveils The New Evolution 9 Spring Drive U.F.A. Ushio 300 Divers
During Watches and Wonders 2025, Grand Seiko unveiled two Spring Drive models powered by a new Ultra Fine Accuracy (U.F.A.) caliber. This year, the Japanese watchmaker follows up on last year’s novelties with two Ushio 300 divers housing a new U.F.A. movement. On top of that, the brand finally granted enthusiasts’ wishes for a smaller Grand Seiko dive watch. Further still, GS equips the new timepieces with a newly developed bracelet that offers all the practicality you could want from a modern watch. Let’s jump in to find out more.
If there has been one big omission in the Grand Seiko collection, it’s been the absence of smaller dive watches. Fans have been begging the brand to develop more reasonably sized divers than the 44–45mm ones it usually puts out. The current Evolution 9 Collection features the SLGA015 and SLGA023, which both have a 43.8mm diameter. Those Evolution 9 divers debuted in 2022, and after four years, they have to make way for the new Grand Seiko SLGB023 and SLGB025, two completely redesigned lightweight titanium divers in blue and green with a new U.F.A. Spring Drive caliber.
The details of the new Grand Seiko SLGB023 and SLGB025
Let’s kick things off with some specs so you can get a good idea of the two new releases. Both feature the same 40.8mm High-Intensity Titanium case with a 12.9mm profile and a 300m depth rating. The new divers belong to Grand Seiko’s Evolution 9 collection, which features a variety of watches with modern case designs. The multifaceted, angular case of the two new models features intricate details. Though predominantly brushed, in true Grand Seiko fashion, it also has some Zaratsu-polished highlights.
I love the natural flow of the new case. Just look at the smooth transition from the lugs to the guards for the screw-down crown on the right side. Could you ask for anything sleeker?
Topping the titanium case is a 120-click unidirectional bezel featuring a ceramic insert that matches the blue or green dial. The bezel markings have remained the same as on previous generations of divers, but the font has changed. The squared numerals feel more modern and match the Ushio dials nicely.
The special Ushio dials of the Grand Seiko SLGB023 and SLGB025
Grand Seiko has offered Ushio dials since 2022. The term ushio (潮) means “tide” in Japanese, and for Grand Seiko, it references the waters that surround the Japanese archipelago. As you can see, the two dials feature this special rippling-water pattern, emphasized by a smooth gradient that gradually darkens towards the edges. The minute track sits neatly on the rehaut, leaving maximum space for the hour markers.
These rectangular indexes feature multiple facets for extra visual impact and a Lumibrite filling that ensures you can read the time in darker conditions. An extra element on the dial is the power reserve indicator located between 7 and 8 o’clock. In all fairness, it does prevent the dial from looking as clean as it could.
What I do like is that Grand Seiko redesigned the hands of these new divers. The brand’s dive watches have long featured cathedral-style hands that have always felt outdated. The new handset looks a lot better and consists of a robust cut-off hour hand and an arrow-shaped minute hand. Both are filled with lume, so you can read the time in low-light conditions. Completing the trio is the razor-thin seconds hand with a lollipop counterbalance.
The Grand Seiko Spring Drive caliber 9RB1 and bracelet are also new
Powering these new divers is the brand’s in-house Spring Drive 9RB1 movement. As mentioned, it is part of the U.F.A. series and runs with an accuracy of ±20 seconds per year. That translates to approximately ±3 seconds per month, which is nothing short of impressive. This 33-jewel caliber has a 30mm diameter and a reasonably thin 4.7mm profile, making it suitable for smaller dive watches. It also offers a healthy 72-hour power reserve.
Finishing the look of the two new Grand Seiko Ushio divers is the newly developed High Intensity Titanium bracelet. It features a predominantly brushed finish, with the links’ beveled edges and sides beautifully polished. This bracelet also includes a new brushed clasp with polished push buttons. The clasp features a toolless micro-adjustment system, offering 6mm of fine tuning. On top of that, it comes with a dive extension that adds 18mm, bringing the total adjustment to 24mm. A nice detail is that the Grand Seiko logo serves as a clever locking mechanism to prevent accidental opening of the clasp.
Final thoughts on the new Grand Seiko Evolution 9 U.F.A. Ushio 300 Divers
We had a chance to try out the new Grand Seiko divers, and they were a breath of fresh air. Their smaller size makes them a great fit for a wider range of wrist sizes. Add lightweight titanium, and you will understand that the watches are super comfortable on the wrist. On top of that, the updated design feels more modern and relevant than that of the previous models. Still, the change from round to rectangular indexes and the oversized hands will undoubtedly lead to strong opinions.
If you ask me, this is a great step in the right direction for Grand Seiko. The most important aspect of these watches is their smaller size. In a highly competitive market, this move was necessary. On top of that, Grand Seiko adds the U.F.A. caliber as a defining feature. It brings both comfort in everyday use and incredible accuracy.
Plus, with the new bracelet and all its modern features, this is a job very well done in terms of updates. But let’s not forget that these watches also feel expertly made and are meticulously finished.
All this makes the Grand Seiko SLGB023 and SLGB025 proper luxury divers. These two new introductions will go on sale in June for €12,500 each. That means they will be €500 cheaper than the ones they replace. It’s great to see that Grand Seiko isn’t raising prices but lowering them for these updated dive watches. What a nice cherry on top!
