71

We go hands-on with the new Grand Seiko Spring Drive U.F.A. Ushio 300 Diver, and see why this is the watch Grand Seiko fans and watch enthusiasts have been wanting!

This year, Grand Seiko upped the ante and took the fight to the swath of other luxury dive watches on the market with the release of its new Spring Drive U.F.A. Ushio 300 Diver, which was released at Watches & Wonders 2026. It was the dive watch Grand Seiko enthusiasts had been wanting and waiting for. A smaller, more wearable diver that was a little more contemporary than the models it replaced.

With a raft of changes, including a smaller, better-proportioned case, a redesigned bracelet, new micro-adjustment and a more modern dial aesthetic, the new Ushio 300 Diver ticked so many boxes. Plus, Grand Seiko decided that steel was too heavy for a sports watch, so they made it from High-Intensity Titanium instead.

We had the privilege of previewing it before Watches & Wonders, and while the article I wrote up for the Grand Seiko Spring Drive U.F.A 300 Ushio Diver was a release with first-hand experience, I’ve held out my thoughts until now for the full review, now that I’ve had time for the watch to marinate in my mind, and time on my wrist.

Initial Thoughts

When I first saw the press pictures and initial specs at the start of the year, I was impressed. Particularly because Grand Seiko had addressed several of the criticisms levelled at its previous Evolution 9 divers. The new Ushio 300 Diver is smaller, lighter, thinner, has a redesigned bracelet and clasp, a cleaner dial and, perhaps most importantly, now has 300 metres of water resistance and the new Spring Drive U.F.A. Calibre 9RB1. So really, it is a whole new watch.

After wearing it for a while, though, the changes are potentially more profound when on the wrist. The 40.8mm case sits comfortably on my 17.5cm wrist, the High-Intensity Titanium keeps the weight down (which can be a good or bad thing, depending on your thoughts on titanium watches), and the redesigned bracelet makes a noticeable difference to how the watch feels throughout the day.

Then there is the dial. I originally picked the green version as my favourite of the two, and after spending time with it, I still think it is the one I would choose. The blue is arguably the more traditional colour for a dive watch, but the green Ushio dial has considerably more depth, and really stands out with the way the texture catches the light. Gun to my head, I would probably choose the green over the blue, but that’s personal preference.

And inside the watch is the second iteration of the Spring Drive U.F.A (Ultra Fine Accuracy). A dive watch that is accurate to ±20 seconds per year makes it one very reliable tool watch. Couple this with a 72-hour power reserve, 300-metre water resistance and a case that measures just 12.9mm thick, you now have a very well-rounded diver.

The Design

The first thing you notice about the Grand Seiko Ushio 300 Diver is the change in proportions. At 40.8mm in diameter, 12.9mm thick and 48.5mm from lug to lug, it is considerably more manageable than some of Grand Seiko’s previous larger dive watches. Grand Seiko says this is the smallest diver it has produced, and that compactness makes a real difference once it is on the wrist. More on that in a little bit.

The case still has the unmistakable Evolution 9 design language, with its broad lugs and combination of brushed and polished surfaces, but the smaller dimensions make the watch feel more cohesive. There is enough case here to give the watch the presence you expect from a serious dive watch, while the lower profile stops it from feeling cumbersome. That and the titanium construction. Speaking of which…

The High-Intensity Titanium is another important part of the design. Grand Seiko uses the material across both the case and bracelet, and the result is a watch that feels unervingly light considering the amount of metal sitting on the wrist. High-Intensity titanium also has a brighter appearance than traditional titanium, which allows the polished sections of the case to stand out more clearly against the brushed surfaces.

The finishing is very much Grand Seiko, with sharp transitions between the different surfaces and plenty of detail when you get up close. It is particularly noticeable around the lugs and case sides, where the polished sections catch the light without making the watch feel overly dressy.

The word Ushio means “tide” in Japanese, with the dial design inspired by the waters surrounding Japan. The blue model moves from a lighter blue through to a much darker outer edge, depicting the deeper ocean, while the green version has a more coastal feel, with lighter green tones and small flecks appearing through the textured surface, mimicking how the water looks closer to the shore. For this reason, I prefer the green thanks to the light play on the dial.

Grand Seiko has also made changes to the dial itself, going for a cleaner look. The date window has gone, leaving the power-reserve indicator at around 7 o’clock as the only additional complication. The hour markers are clean and modern, with faceted edges and filled with Lumibrite, while the hands have also been redesigned with a sharper, more angular appearance. This all provides a nice, clean, and highly legible dial, which is the essence of what a dive watch should be.

Now it would be remiss of me to talk about the design without talking about the bracelet and clasp. Grand Seiko has developed a new locking extension clasp for the Ushio Diver, giving you 6mm of micro-adjustment for everyday wear and an additional 18mm dive extension when you need to wear the watch over a wetsuit. There is also a locking mechanism on the clasp that prevents the pushers from being accidentally operated when diving.

In practical terms, the clasp feels much more refined than some of the earlier Grand Seiko dive watch hardware. The micro-adjustment is easy to use, and having the two independent adjustment systems means you can get a much better fit whether you are wearing the watch normally or actually taking it into the water. And this is a good segue to the next section.

How It Wears

I have worn plenty of dive watches over the years, and up until very recently, they were my go-to watch style thanks to the durability and the look. But as my tastes are changing, the bigger, bulkier dive watches are becoming less and less appealing to me, and this is where I always shied away from Grand Seiko with the larger-sized dive watches. I feel many enthusiasts were in the same boat, and it was one main criticism of the dive watches Grand Seiko produced. But not any more!

On my 17.5cm wrist, the 40.8mm case sits nicely across the wrist, with the 48.5mm lug-to-lug keeping everything within the wrist’s edges. The 12.9mm thickness is also reasonable for a 300-metre dive watch, as there are not many others out there with that level of water resistance that would be much thinner than about 12mm.

The titanium makes an immediate difference as well. There is a certain expectation that a substantial dive watch should have some heft to it, as let’s face it, these are normally a decent chunk of metal on the wrist. The Grand Seiko Ushio 300 Diver feels very different due to the titanium case and bracelet. This is one area where I struggled to get my head around it.

It is there when you look down at it, but it does not constantly remind you that you are wearing a large, heavy piece of metal. Now I don’t want a massively heavy watch on my wrist, but there is something slightly strange about a full titanium-constructed dive watch. I felt this about the Tudor Pelagos and also about the Rolex Yachtmaster – although it’s not a dive watch, it is dive-watch-styled. It messes with your head a little. However, put a titanium watch on rubber, and I’m good to go – yes, call me crazy!

That said, the Ushio Diver is insanely comfortable. The links move well, and the combination of brushed and polished surfaces works with the case rather than making the bracelet feel like an afterthought, as some brands do. More importantly, the new clasp allows you to make small adjustments during the day, which is useful when your wrist changes size with temperature. See my previous points on the micro-adjust.

Colour-wise, both are great, so it really comes down to personal taste. The blue is classic, and probably ever so slightly more versatile, but the blue doesn’t stand out as much, nor does it have as much depth. The green dial is less versatile, but the dial stands out more thanks to the design. In saying this, the green dial still works as an everyday watch. It has enough colour and texture to stand out, but because the outer edge becomes darker and the green is not a bright green, you can get away with wearing it on different occasions.

That is something I have always looked for in a dive watch. I am not spending my days scuba diving, so if a watch is going to sit in my collection, it needs to work just as well at a desk, out for dinner or walking around on the weekend. I feel the Grand Seiko Ushio 300 Diver does this well.

The Movement

Inside the Ushio 300 Diver is Grand Seiko’s Spring Drive U.F.A. Calibre 9RB1, a variation of the Calibre 9RB2 we saw introduced in the Evolution 9 collection last year. If you’re not familiar with the Spring Drive U.F.A, then here’s a quick summary.

U.F.A. stands for Ultra Fine Accuracy, and the 9RB1 has an annual accuracy rating of ±20 seconds. That works out to approximately ±1.6 seconds per month, which is an extraordinary figure for a mechanical watch.

The 9RB1 is closely related to the Calibre 9RB2 introduced in 2025, but Grand Seiko has made several changes for the Ushio Diver. The date has been removed, allowing the movement to be more compact, while the power-reserve indicator has been moved from the back of the movement to the dial side. This also allowed Grand Seiko to use a closed caseback, which makes sense on a 300-metre dive watch. A closed caseback means a slimmer profile and greater water resistance.

The Calibre 9RB1 also uses Spring Drive technology. The quartz crystal oscillator is aged for three months before being vacuum-sealed together with the integrated circuit, helping to reduce the effects of temperature, humidity, static electricity and light. Grand Seiko also measures each oscillator at multiple temperatures and uses that data for temperature compensation.

Like all Spring Drive movements, it is a fusion of mechanical and non-mechanical technology, or as some would say, the old and the new. The rotor coupled to the mainspring provides the energy, while the electronic regulation system controls the release of that energy to produce the smooth, continuous motion of the seconds hand, making it the smoothest sweep in the watch world.

The 9RB1 also has a 72-hour power reserve and magnetic resistance of 4,800 A/m, which converts to about 60 gauss. This is one area I would have liked to see improved is the magnetic resistance. At 4,800 A/m, or 60 gauss, it is on the low side, especially when you consider modern life puts watches around more magnetic fields than ever.

As a comparison, the Omega Seamaster Diver is anti-magnetic to 15,000 gauss, and other dive watches are rated to well over 1,000 gauss. To put this into real-life terms, an iPhone emits about 50-100 gauss at the surface, but then drops to below 10 gauss once you are 1-2 cm away. So, don’t rest your Ushio Diver on your iPhone very often.

That aside, there is very little to complain about with the 9RB1. It is an extremely accurate and reliable movement that makes perfect sense in a modern dive watch, plus it is hand-assembled at the Shinshu Watch Studio in Shiojiri, so you are getting that Grand Seiko hand-made touch as well.

Final Thoughts

Coming back to my original thoughts after spending some proper time with the Grand Seiko Spring Drive U.F.A. Ushio 300 Diver, I still think this is one of the strongest releases Grand Seiko has produced in the dive watch category. It is a big call, but I stand by it.

Why? For one, it feels like Grand Seiko has listened to what collectors have been asking for. The previous Evolution 9 divers had plenty going for them, but the size and proportions were not for everyone. The new Ushio 300 Diver addresses that with a smaller case, lighter titanium construction, a better bracelet and a much more sophisticated clasp.

Then you add the 300-meter water resistance and the Spring Drive U.F.A. Calibre 9RB1, and you have a watch that is a high-performing dive watch in every sense of the word.

I still think the green is the pick of the two, although the blue will probably be the safer choice for anyone looking for something a little more traditional. The Ushio dial gives both watches enough personality to separate them from the sea of black and blue dive watches on the market, while the cleaner dial layout makes them easier to live with day to day.

At A$17,700, the Ushio 300 Diver is not inexpensive, but it is also sitting in a part of the market where the competition is now pretty fierce. You have the Rolex Submariner now priced at A$16,850 and the date variant at A$18,950 in black, or A$19,850 with the green bezel. The aforementioned Omega Seamaster Diver is considerably less at A$11,550 for the new generation on steel, but if you want the lightness of titanium, then this jumps to A$17,825.

And of course, there are a plethora of other high-end dive watches out there: Blancpain Fifty Fathoms starting at A$25,500, Zenith’s Extreme Diver at $19,100, and even Panerai with its Submersible is now north of A$19,000. I could go on, but you get the gist.

What I will say is that if you are looking beyond the obvious choices – and I feel these days many people are, including me, then the Grand Seiko Ushio 300 Diver deserves to be on the list.

References & Specifications:

Feature	Specification
References:	SLGB023 – Blue / SLGB025 – Green
Dimensions	40.8 mm diameter x 12.9 mm thickness x 48.5 mm lug-to-lug
Case Material	High Intensity Titanium, brushed and polished with a screw-down crown
Case Back	Screwed-down case back
Dial	Blue or green gradient “Ushio” textured dial. Diamond-cut markers and hands filled with Lumibrite. 120-click dive bezel with ceramic insert.
Crystal	Sapphire crystal with anti-reflective coating on the inner surface
Movement	Spring Drive U.F.A. Calibre 9RB1 automatic winding movement, accurate to ±20 seconds per year
Power Reserve	Approx. 72-hour power reserve
Water Resistance	30 bar (300 metres)
Bracelet	High-Intensity Titanium, brushed and polished with a push-button folding clasp, including 6mm comfort and 18mm dive extensions, plus locking mechanism

Australian Retail Price: A$17,700

Availability: Available now via Grand Seiko boutiques, Grand Seiko retailers or online at Grand-seiko.com

Full Image Gallery