Off the Cuff: Spinnaker Dumas GMT

Last year in 2022, Seiko made a major contribution to horology by releasing the NH34 GMT movement. Not a Rolls Royce of GMT calibers by any means, but an affordable GMT movement made by a massive player that has a track record for democratising horology. The NH34 changed everything. It makes travel watches attainable for a larger portion of the watch nerds population all the while making us feel like we are not compromising on quality. That is huge and something that we couldn’t get before. Now there are several options for affordable GMT watches using the NH34 coming from the micro/independent world at prices that range (roughly) between $250 to $750. 

Spinnaker Dumas GMT Review
Spinnaker Dumas GMT

There exists, therefore, the perfect opportunity to match a great movement with a great brand. Or, to be more specific, matching a capable and affordable GMT movement with a brand that knows how to make attractive, well-spec’d, and reasonably-priced horology. Enter Spinnaker and its latest model, the Dumas GMT. Dumas is Spinnaker’s collection of hardcore divers that boasts incredible specifications and depth ratings. Now, Spinnaker added a GMT variant which gives you a lot of watch for your hard-earned cash. Let’s take a look.

Spinnaker Dumas GMT Review
300m water resistance

In general, Spinnaker watches tend to be larger than I would prefer. Which could be a problem for a type of watch that would normally look better, smaller. But there are certain types of watches that need to be larger, or at least that look the part by coming with larger dimensions. This is the case for divers that have depth ratings above 200 meters. And although I’ve come across 1,000 meter divers with mid-sized cases, there is something cool about a beefier watch. That is the case with the Dumas GMT that comes with a diameter of 44mm, a lug-to-lug of 48mm, a thickness of 15mm and a lug width of 22mm. The Dumas GMT is by no means a small watch; however the short lug-to-lug makes it wearable on my 6.25”/16cm wrist.

Spinnaker Dumas GMT Review

You wouldn’t be surprised to know that this watch is powered by the Seiko NH34 GMT movement which beats at 21,600 BPH (3Hz) and comes with 41 hours of power reserve. It is a “caller GMT” movement, meaning it is the GMT hand that jumps back and forth and not the local hour hand. This type of GMT makes more sense for someone like me who likes to know what time it is somewhere else on our little blue planet and who doesn’t need to cycle through time-zones like a transcontinental commercial pilot. Adjusting the GMT to another timezone is quick, and one can also use the bi-directional bezel to change time zone (or track a third one) in a couple of seconds.

Spinnaker Dumas GMT Review
24-hour bezel, coupled with Seiko’s NH34 GMT

Furthermore, the Dumas GMT boats 300 meters of water resistance and a see-through case-back, showcasing a customized rotor. The crystal atop the dial is made of sapphire that comes with anti-reflective coating. There is ample lume on the plongeur-style hands and applied hour markers as well as on the bezel insert. There is a small framed date window at the 6’clock, complementing the functionality of the Dumas GMT. Lastly, the watch is delivered with a full stainless steel bracelet and a customized rubber strap, both equipped with quick-release spring-bars. The bracelet has solid links and end-links and a diver’s extension nestled inside the short and thin clasp.

Spinnaker Dumas GMT Review



Case316L Stainless Steel
34mm Diameter
48mm Lug to Lug
15mm Thick
22mm Lug Width
Screwed Crown & Display Case Back
300m Water Resistance
Dial & CrystalSapphire Crystal
Plongeur Hands
Applied Indices
MovementSeiko NH34
21 600bph
24 Jewels
41-Hour Power Reserve
StrapStainless Steel Bracelet

Spinnaker Dumas GMT


Of Interest

Given that more and more brands are coming up with their own versions of affordable GMTs utilizing the Seiko NH34 movement, each brand must up the ante with each release. The name of the game now is to provide maximum value to stand out from the crowd. In this respect, the Dumas GMT offers a lot of value for the asking price of $550. Not only a GMT movement, 300 meters of water resistance, a bracelet and rubber strap, and a see-through case-back, but also a handsome dial that is well-finished and handsomely laid out. (Of course, that’s a matter of personal preferences.) While I wish the case would have been smaller, the Dumas GMT fits well on my small wrist. This means I can wear a spec-monster GMT for a somewhat reasonable amount of cash.

Spinnaker Dumas GMT Review
Unique flair

The Dumas GMT constitutes my first experience with the Dumas line of watches from Spinnaker. Looking at their website, it is easy to tell they have a unique flair. The case has an octogonal shape where the bracelet seems to pop from its underside, while the plongeur-style handset makes the dial balanced. The dwarfed hour hand is painted orange while the massive sword-shaped minute hand is silver, and the GMT hand is blue and has a blacked-out stem. At certain angles, the GMT hand appears to be floating above the dial which is a pretty neat visual effect. Furthermore, the juxtaposition of applied hour markers and a raised minute track add dimension to the dial. It is, overall, a dynamic design that looks cool.

Spinnaker Dumas GMT Review
Hidden lugs

Making GMTs legible seems to be a difficult task. Many times I’ve handled GMTs that have too much going on the dial which makes reading the local and GMT times difficult. I like that Spinnaker decided to combine this particular handset with two GMT scales, one printed at the base of the raised minute track and the other on the bi-directional bezel. It is rather easy to track the time in two additional time-zones this way whilst being able to keep track of local time. It would be great if Spinnaker were to offer a version of the Dumas GMT with a dive-time bezel insert to add another functionality to the watch.

Spinnaker Dumas GMT Review
Octagonal case


As you might have gathered by now, the Dumas GMT is a big watch. While I know that the Dumas are designed to be big and look badass, I wish Spinnaker would make a smaller version. Something in the 40 x 46mm dimensions to fit smaller wrists. I believe—but don’t quote me on it—that technically this would be possible. “Technically” in the sense that the watch could have 300 meters of water resistance and a GMT calibre whilst being smaller. However, I must acknowledge the fact—yet again—that all Dumas are chunky and I applaud Spinnaker for adding a GMT variant of their popular diver to fit the needs of more watch enthusiasts.

Spinnaker Dumas GMT Review
Multifaceted links and small

Moreover, I would suggest to Spinnaker to offer the option for a stretch fabric strap à la Marine Nationale in addition to the rubber strap. The latter is thick and makes the watch look bulkier than it does on the stainless steel bracelet, something that surprised me a little. Being a bigger watch, a thinner strap that has stretch would reduce the watch’s bulky appearance and make it more comfortable to wear. However, I must say the stainless steel bracelet is good. Its multifaceted links and small clasp balance out its weight. Another quick suggestion: replace the pins with screws.

Spinnaker Dumas GMT Review
Spec monster

Final Thoughts 

The competition for affordable GMTs is fierce. There are cheaper options than the Dumas GMT and there are more expensive ones. At the end of the day it comes down to what looks good to you and which specs are the most important. Is it the movement, water resistance, or the bezel action? I didn’t cover everything here as the Dumas comes with many neat details which—to me—makes it a compelling offer. For example, the mentions of “AM” and “PM” on either side of the date aperture to help our American friends use the GMT scales. (I know quite a few US-based watch enthusiasts who struggle using the 24-hour scale. I feel for you my friends!)

The Dumas GMT is available for purchase starting April 28th, 2023, for the price of $550. It comes in four colour variants—Cobalt Crimson (black dial/red and blue bezel) Dark Turquoise (black dial/turquoise accents) Navy Black (blue dial/black and blue bezel) and Harbour Grey (black dial/black and grey bezel)—and each variant comes with a colour-matched rubber strap. You can learn more about the Dumas GMT on the brand’s website.


Vincent Deschamps is a museum professional, originally from France, with more than 10 years experience as a researcher, producing visitor experiences for national and international organizations. He is also the founder of You can follow Vincent on Instagram.

Off The Cuff articles are full-length, hands-on reviews of the watch in question and represent the opinion of the author only. All photos are original, unless specified otherwise. If you would like to have your watch reviewed on this site, contact us here.

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5 thoughts on “Off the Cuff: Spinnaker Dumas GMT

  1. The Pepsi looks great and the distinct case is a nice touch. Great one by Spinnaker.

    1. I want a GMT fairly badly, not because I’m a jet-setting traveler, but just for the cool factor. I’d love to see what these look like in person. I got a Spinnaker Croft from some dude a while back, he gave me my first look at Spinnaker and since then I’ve had a huge appreciation for their pieces…wonder what that guy is up to these days 🤔😁

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