G-SHOCK GMC-2500 & GAC-2500 Hands-On Review: Meet the New CasioNaut

Hey Watchfam!

I think Casio might be about to cause me a few problems. Mainly because I'm going to need to find some more space in my G-SHOCK collection!

Every now and again, G-SHOCK introduces something that feels genuinely new. Not another colourway or special edition of a watch we've seen before, but a fresh design that makes you sit up and take notice.

I remember having that feeling when the original GA-2100 CasiOak came along, and as someone who now owns probably a dozen different versions, it's fair to say that one worked out rather well for Casio!

Well, I had a similar feeling when I first got my hands on the new G-SHOCK GMC-2500 and GAC-2500 series.

Earlier this year, I had the opportunity to spend a couple of weeks with the entire collection, wearing and photographing all nine watches. And I have to say, I was impressed pretty much as soon as I started taking them out of their boxes.

They have that familiar solid G-SHOCK feel I've come to expect, but the case design is something quite different. And the more time I spent with them, the more I started imagining which versions I'd actually wear and when.

Usually, I can look at a new collection and pick a favourite fairly quickly.

Not this time!

Meet the CasioNaut – A New G-SHOCK Design

If you've been following the watch news lately, you might have already spotted the nickname CasioNaut doing the rounds.

It seems the watch community has been busy again!

Much like the GA-2100 became known as the CasiOak because of its resemblance to the Audemars Piguet Royal Oak, these new models have picked up the CasioNaut nickname thanks to their passing resemblance to the Patek Philippe Nautilus.

You can see where that comparison comes from. The rounded case, broad shoulders and almost cushion-like shape certainly have something of that famous luxury sports watch about them.

But personally, I think these still look very much like G-SHOCKs.

Casio's official inspiration actually goes back to the original DW-5000C from 1983, with the idea being to take some of that first watch's functional design and develop it into something new with a fully analogue dial.

And I really like what they've come up with.

The case is an interesting mixture of softer curves and more defined edges. You have that rounded-square opening around the dial, but the shoulders at either side give it a more substantial appearance.

There's also something I particularly like about the way the case changes shape as you look at it from different angles. It isn't just a flat bezel sitting on top of a straightforward case. The sides curve and flow into those more prominent shoulders, giving it quite a distinctive profile.

On the metal versions, the finishing helps bring those shapes to life.

The broad brushed bezel contrasts beautifully with the polished surfaces around the sides and where the bracelet or strap meets the case. And I think that's part of what makes these watches look a little more refined than you might expect from G-SHOCK.

The familiar G-SHOCK branding across the top of the bezel and PROTECTION lettering at the bottom are nice reminders of where the watch comes from, too.

It's a fresh design, certainly, but it hasn't forgotten what it is.

How Does the New G-SHOCK Wear?

This was actually one of the first things that impressed me.

I've owned and reviewed plenty of G-SHOCKs over the years, and although I love the brand, some of its larger models can be a little imposing on the wrist.

My wrist measures just over seven inches, so I don't have particularly large wrists, and I found these new watches fitted me really well.

The case has plenty of presence, as you'd expect, but the proportions feel nicely judged. Those rounded sides and the way the watch flows into the bracelet or strap help it sit comfortably without feeling awkward.

Looking at the wrist shots, you can see that they're certainly not tiny watches, but I never felt they were unnecessarily large.

And that's something I appreciated throughout my time with them.

Of course, the weight changes considerably depending on which version you're wearing, and that's where things become interesting.

Full Metal, Metal and Resin, or Full Resin?

Casio has launched nine watches across three different material combinations.

There are two full-metal GMC-2500D models, three GMC-2500 models with metal cases and resin straps, and four full-resin GAC-2500 models.

We've seen Casio take this approach with other G-SHOCK collections, but I think it works particularly well here.

In fact, photographing the different versions was fun because the same design takes on quite a different appearance depending on the materials and colours.

The Full-Metal GMC-2500D Models

Let's start with the full-metal versions.

If you already own one of G-SHOCK's full-metal watches, you'll know exactly what to expect when you pick one of these up.

They feel solid, substantial and reassuringly weighty.

The bracelets have that familiar G-SHOCK construction, with broad brushed links that match the finishing on the case. There's nothing particularly surprising here, but I don't mean that as a criticism. They're well made and feel exactly how I'd expect them to.

The two launch colours are black and blue, both paired with silver-coloured cases and bracelets.

And for me, the blue GMC-2500D-1A2 is the standout of the entire collection.

It's a lovely shade of blue, slightly muted rather than overly bright, and there's a subtle texture to the dial that becomes more noticeable as the light moves across it.

Then you've got those polished hour markers and hands, which really stand out against the darker background.

The contrast between the brushed steel bezel, polished case surfaces and that blue dial is just beautiful.

The black version is a little more understated and will probably appeal to anyone who wants something that works with pretty much everything.

Both have a more grown-up feel than the resin watches. I wouldn't call them dress watches, because that would be a bit of a stretch! But I could certainly see myself wearing one when I wanted something a little smarter.

Now, there's one thing I'd change about the blue version for my own use.

I'd put it on a resin strap.

Not because there's anything wrong with the steel bracelet, but simply because I tend to prefer lighter watches, particularly for everyday wear.

Provided a suitable compatible strap is available, that's probably how I'd choose to wear it.

I know some people absolutely love the weight of a full-metal G-SHOCK, and I completely understand the appeal. It's just a matter of personal preference.

The Metal GMC-2500 Models on Resin Straps

Now, these might actually be my favourites from a practical point of view.

You still have the metal case, with all those lovely brushed and polished surfaces, but the resin strap makes the watch feel considerably more relaxed.

It's a combination I've always liked with G-SHOCK, and I think it suits this design beautifully.

There are three options here: black, silver and gold.

The black and silver models are both attractive, but I have to give a special mention to the GMC-2500G-9A.

This is one of those watches that surprised me.

I'm not generally someone who gravitates towards gold watches. I've seen plenty of gold G-SHOCKs over the years, and although I can appreciate them, they're not usually something I'd choose to wear.

But this one is different.

The colour is much softer than you might expect, with a pale champagne-gold finish that looks really lovely in person.

And the dial is particularly nice.

Rather than being a highly polished, mirror-like gold, it has a fine, almost grainy texture that gives it a softer appearance. The warmer gold-toned hands complement the dial, while the raised hour markers provide a little contrast.

Paired with the black resin strap, I think it works beautifully.

There's enough gold to make it feel special, but not so much that it becomes overpowering.

I could easily imagine wearing this one with a shirt or something a little smarter for an evening out, while still having that comfortable, casual feel of a G-SHOCK on a resin strap.

I really didn't expect to like this version quite as much as I did.

And that's probably why it's one of the watches I'd seriously consider buying.

The resin straps themselves are familiar G-SHOCK fare, with a fine textured pattern that looks particularly nice against the smoother metal cases.

They could perhaps be a touch softer and more flexible, which is something I've said about other G-SHOCK straps in the past.

But they're comfortable enough, and the lighter wearing experience is worth it for me.

The Full-Resin GAC-2500 Models

Then we come to the resin versions, and these are great fun.

There are four launch colours: black, dark green, white and a lovely warm yellow.

All four have that classic G-SHOCK feel, with their solid resin cases and straps, but they look very different from the metal models.

The surfaces have a flatter, more uniform finish, which really suits the design.

And while the metal models use their polished surfaces and dial finishing to create a more refined look, the resin versions have a slightly more playful character.

Take the warm yellow GAC-2500-9A, for example.

It's a rich, sunny yellow rather than anything particularly bright or neon, and I think it looks fantastic.

The matching dial and strap give the watch a wonderfully cheerful appearance, while the white hands and darker details stop the whole thing becoming difficult to read.

I could easily see myself wearing this one through the summer, particularly on holiday or spending a day by the pool.

The white GAC-2500-7A is another favourite.

I really like white G-SHOCKs, and this one has a particularly clean appearance. Almost everything is white, from the case and strap through to the dial and hour markers.

You might expect that to make it difficult to read, but I found the legibility surprisingly good.

The darker minute markings and date numerals help, while the raised hour markers and hands give the dial enough depth that everything doesn't simply blend together.

It's a fresh-looking watch, and I actually think it would look just as good in winter as it would in summer.

Then there's the dark green GAC-2500-3A.

This one has a much more rugged appearance, and I think it's a great colour choice.

I particularly like the small orange accents on the dial. They're easy to miss at first, but they add a little contrast without spoiling that understated green finish.

It's exactly the sort of watch I could imagine wearing on a hike or just wanting something a little more outdoorsy on my wrist.

And finally, we have the black GAC-2500-1A.

It's a classic look, and I'm sure plenty of people will gravitate towards it.

Personally, though, I already own quite a few black G-SHOCKs, so I'd probably choose one of the other colours.

To be honest, I could see myself owning all three of the yellow, white and green models.

And that's what I find so appealing about this collection. I can imagine wearing those watches in completely different situations, even though they're all based on exactly the same design.

The Dial – One of the Best Things About the CasioNaut

I think the dial is a real strong point across the collection.

It's simple, well laid out and easy to read, but there's enough going on to stop it looking boring.

And that's not always an easy thing to get right with an analogue G-SHOCK.

You've got large hands, nicely sized hour markers, a small subdial at nine o'clock and the new date display sitting at three.

The layout works really well.

One detail I particularly appreciate is the way the hour markers sit slightly raised from the dial. It gives everything a bit more depth, especially when viewed from an angle.

The metal models benefit from more polished-looking markers and those lovely metallic dial finishes, while the resin versions keep things a little simpler.

Neither approach feels wrong for the watch.

If anything, I think it's one of the reasons the design works so well in both materials.

And that isn't something I feel about every G-SHOCK.

I've always loved the classic digital squares, but try as I might, I've never completely fallen in love with some of the highly polished full-metal versions.

I know, controversial!

There's something about the original square's utilitarian design that, for me, feels particularly at home in resin.

With the CasiOak, however, I thought the move to metal worked brilliantly. I felt that way when I reviewed the G-SHOCK GM-2100 Steel CasiOak, and I think Casio has managed something similar with these new models.

The analogue dial and case shape just seem to suit the more polished finishes.

And perhaps most importantly, the watches remain really easy to read.

Even the lighter-coloured resin models offered excellent legibility during my time with them.

I know that sounds like something every watch should get right, but as anyone who has owned a few analogue G-SHOCKs will know, it isn't always guaranteed!

Multi-Mission Date – A Clever Little Feature

There's an interesting new feature on these watches called Multi-Mission Date.

Look at the three o'clock position and you'll notice a small window with three cells.

Rather than having a conventional date window that only does one job, this display changes the information it shows depending on what you're doing.

During normal timekeeping, it shows the date. When you're using the stopwatch, it can display elapsed minutes, and it can also provide information when adjusting the watch's settings.

It's a clever way of adding a little extra functionality without introducing a conventional digital display.

Casio has also managed to incorporate a fully automatic calendar into this entirely analogue layout, so once you've set the date correctly, you don't have to keep adjusting it for shorter months.

There's another small feature at nine o'clock, where the seconds hand can be stopped when you don't need it.

The hand can then be restarted when required, helping to reduce power consumption and extend battery life.

Both are useful little additions, although they're not necessarily the reason I'd buy one of these watches.

For me, the appeal is much more about the design and how they wear.

And in everyday use, there's very little to complain about.

The buttons protrude just enough to make them easy to operate without interrupting the shape of the case, and the functionality feels familiar if you've spent any time with other G-SHOCK watches.

Would I choose one of these for serious sports tracking or marathon training?

Probably not.

There are other watches better suited to those sorts of activities, and that's absolutely fine.

These feel more like attractive, practical everyday G-SHOCKs rather than something designed around a long list of fitness features.

The same goes for the illumination.

No, I didn't take them out on some sort of midnight military exercise to see how they performed!

But for normal use, I found it perfectly adequate. If you wake up in the night and want to check the time, press the button and you can read the dial.

Job done.

If nighttime legibility were one of my main priorities, I'd probably look at a fully digital model instead. Something like the G-SHOCK GW-BX5600 with its MIP display would be a more obvious choice.

But that's a different sort of watch with a different purpose.

Could the CasioNaut Be the Next CasiOak?

This is what I keep coming back to when I think about the GMC-2500 and GAC-2500.

When the original GA-2100 arrived, it was a genuinely exciting new design for G-SHOCK.

It was distinctive, wearable and offered something that felt quite different from the existing range.

I remember reviewing the original GA-2100 CasiOak, including that famously difficult-to-read all-black version, and being really impressed by what Casio had done.

Since then, the range has grown into a huge collection of different colours, materials and specifications.

And I've bought rather a lot of them along the way!

I think this new series has some of that same potential.

The easiest way I can describe it is as a more grown-up take on the CasiOak's appeal.

Not necessarily better, because I still love my GA-2100s, but a little more mature in its styling, particularly when you look at the metal versions.

Even compared with some of the steel CasiOaks I've owned, there's something about this design that feels slightly more refined.

Will it turn out to be as successful as the original CasiOak?

I've no idea.

I remember how popular some of those early models became, especially the all-black version, and I certainly wouldn't be surprised if a few of these new watches prove particularly sought-after.

Of course, some enthusiasts will be hoping for additional features such as Tough Solar.

And I can understand that.

But we saw Casio introduce the original GA-2100 before later adding versions such as the GA-B2100 with Tough Solar and Bluetooth.

Whether we'll see the same sort of development with this new series remains to be seen, but I certainly hope we do.

Personally, though, there's nothing I experienced with these watches that would make me want to hold off buying one while waiting for a more feature-rich version.

I think Casio has got the important things right already.

Which GMC-2500 or GAC-2500 Would I Buy?

Now, this is the difficult bit.

If I could only choose one from the entire collection, I'd probably go for the blue-dial GMC-2500D-1A2.

I really love that dial, and the combination of brushed and polished steel gives the watch a lovely appearance.

Ideally, I'd wear it on a resin strap if a compatible option is available, but either way, it's a watch I'd be very happy to have in my collection.

Then there's the pale gold GMC-2500G-9A.

That one really surprised me.

It's not a colour I'd normally gravitate towards, but the softer champagne finish makes it much more wearable than I expected.

And if I were choosing a resin version?

Well, I'd struggle to settle on just one.

The yellow would be brilliant for summer, the white feels fresh enough to wear all year round, and the dark green is ideal for something a little more rugged and understated.

I think that's one of the nicest things about this initial collection.

As soon as I unboxed the watches, I could imagine wearing different versions for different occasions.

And by the time I'd finished spending time with them, that initial feeling hadn't changed.

If anything, I was even more convinced that more than one of these could find its way into my collection.

G-SHOCK GMC-2500 and GAC-2500 UK Prices

Now that we have the official UK prices, I think Casio has positioned this new collection quite nicely.

The full-resin GAC-2500 models are priced at £110, regardless of which colour you choose. And personally, I think that's a pretty attractive starting point for what feels like a genuinely new G-SHOCK design.

Move up to the metal-case GMC-2500 models with resin straps and you're looking at £230 for the black and silver versions, while that lovely champagne-gold GMC-2500G-9A comes in at £250.

Finally, the full-metal GMC-2500D models, including my favourite blue-dial version, are priced at £300.

That's quite a range, but having handled all these watches, I can appreciate the differences. The metal versions have a noticeably more premium look and feel, with their brushed and polished cases and more refined dial finishes.

Whether those upgrades are worth the additional cost will ultimately come down to what you enjoy wearing.

For me, I think the resin models at £110 are particularly appealing, although that blue-dial full-metal version is still calling my name!

And with only £70 separating the standard metal-and-resin models from the full-metal versions, I can certainly see the appeal of spending a little extra if you prefer a steel bracelet.

Whichever version you choose, I think Casio has given us an interesting selection across several different price points.

Final Thoughts – Has G-SHOCK Done It Again?

So, after having the opportunity to spend a couple of weeks with the new CasioNaut collection, what do I think?

Well, I really enjoyed these watches.

And if I'm honest, I was pretty much sold on the design from the moment I started unboxing them.

It's refreshing to see G-SHOCK introduce something that feels genuinely different, especially when the brand already has so many successful designs in its collection.

The case looks fantastic, the proportions worked really well on my wrist, and I particularly like how clean and easy to read the fully analogue dial is.

Then there's the choice of materials.

I love the more refined feel of the metal versions, particularly that blue dial and the lovely champagne-gold model, but the resin watches have plenty of appeal in their own right.

For everyday comfort, I'd probably choose a resin strap over a steel bracelet, and I wouldn't mind the straps being a little softer.

But those are personal preferences rather than things that would put me off buying one.

What impressed me most was how easily I could imagine adding these watches to a collection that already has plenty of G-SHOCKs in it.

They don't feel like another version of something I already own.

They feel like something new.

And that reminds me very much of how I felt when the original CasiOak arrived.

I don't know whether the CasioNaut will go on to enjoy the same success, but I think Casio has made a really promising start.

There's a lovely selection of models here, the design works brilliantly in both resin and metal, and I can certainly see it developing into another popular G-SHOCK family over the coming years.

As for me, I just need to decide which one I'm going to buy first.

Although knowing how my G-SHOCK collection has grown over the years, I suspect stopping at one might be the bigger challenge! 😂

G-SHOCK GMC-2500 and GAC-2500 – All Nine Launch Models

• GMC-2500D-1A – Full-metal model with a silver-coloured metal case and bracelet, paired with a black dial.

• GMC-2500D-1A2 – Full-metal model with a silver-coloured metal case and bracelet, paired with a textured blue dial.

• GMC-2500-1A – Silver-coloured metal case, black dial and black resin strap.

• GMC-2500-1A8 – Silver-coloured metal case, silver dial and black resin strap.

• GMC-2500G-9A – Gold-coloured metal case with a softly textured, champagne-like gold dial and black resin strap.

• GAC-2500-1A – Black resin case and strap with a matching dark dial.

• GAC-2500-3A – Dark green resin case and strap, matching green dial and small orange accents.

• GAC-2500-7A – White resin case, strap and dial, with raised hour markers and contrasting date numerals.

• GAC-2500-9A – Warm yellow resin case and strap with a matching yellow dial.

G-SHOCK CasioNaut Frequently Asked Questions

What is the G-SHOCK CasioNaut?

CasioNaut is the nickname watch enthusiasts have given the new G-SHOCK GMC-2500 and GAC-2500 collection. The name comes from the resemblance between the watch's rounded case and distinctive shoulders and the Patek Philippe Nautilus. It isn't an official Casio model name.

What's the difference between the GMC-2500 and GAC-2500?

The GMC-2500 models have metal cases and are available with either metal bracelets or resin straps. The GAC-2500 versions have resin cases and straps, making them lighter and giving them a more casual appearance.

Are the GMC-2500 and GAC-2500 fully analogue?

Yes. Both series have fully analogue displays with traditional hands and the new Multi-Mission Date window at three o'clock, rather than a conventional LCD screen.

What is G-SHOCK Multi-Mission Date?

Multi-Mission Date is a three-cell display that shows different information depending on the function being used. It can display the date, elapsed stopwatch minutes and information while adjusting settings. It also enables a fully automatic calendar.

Are the new G-SHOCK CasioNaut watches comfortable to wear?

I found them very comfortable during my time with the collection. The case sits nicely on my just-over-seven-inch wrist, although the full-metal models are noticeably heavier than the resin versions.

Which G-SHOCK CasioNaut would I choose?

My overall favourite is the blue-dial GMC-2500D-1A2, although I also really like the champagne-gold GMC-2500G-9A. For something lighter and more casual, the warm yellow, white and dark green resin models would all be strong contenders.

If you fancy taking a closer look at the new collection, you can check out the full range over at G-SHOCK UK. And I'd love to hear what you think of these new models! Which one is your favourite? Let me know in the comments below, because I'm curious to see whether you guys are as impressed with this new series as I am!