A Week On The Wrist: The Seiko Prospex SPB381 GMT
From callers and flyers to dual times and more, the past few years have seen a specific increase in the popularity of the travel watch. In part kick-started by the 2018 release of Tudor’s Black Bay GMT, fans of travel watches have witnessed a mounting of arms in the mechanical sub-luxury space. New movements have led to new watches, and increased competition in the space has made it a buyer’s market that manages to offer an incredible amount of variety in terms of sizing, functionality, and scope. Earlier this year, Seiko threw its own hat in the ring with a Prospex-derived trio of premium mechanical dive GMTs, including this one, the gregariously green SPB381.
Officially named the Seiko Prospex 1968 Diver’s Modern RE-Interpretation GMT, the SPB381 – along with the black dial SPB383 and light-blue dialed limited edition SPB385 – pulls familiar inspiration from Seiko’s enduring and well-loved history with dive watches. With its Marine Master good looks, squared shoulders, and elapsed time bezel, from a distance, you might think this is just another handsome diver from Japan. But Seiko took the formula a step further with the SPB38X models and fitted a new movement with a 24-hour hand that can easily track a second time zone.
The SPB381 measures 42mm wide, 13.3mm thick, and 48.1mm lug to lug and comes on a steel bracelet. Both the case and bracelet have Seiko’s “Super Hard” treatment for scratch resistance, and the SPB381 has an anti-reflective sapphire crystal, a closed steel case back, drilled lugs, 200 meters of water resistance, and, in an uncommon move for a Seiko diver, a ceramic bezel insert.
Opting for a green-on-green colorway with a light use of golden accents, the SPB381’s dial is a rich, almost metallic green with a sunburst finish. In contrast, the ceramic bezel insert features a green with much more brown-yellow in the mix. In bright light, the two greens are easy to differentiate, but the colors become much closer to dark green (or even black) in darker scenarios.
With applied white metal markers and matching hands, the gold accents highlight the GMT functionality of the watch, with both the “GMT” text on the dial and the 24-hour hand carrying a yellow gold finish. The 24-hour hand points to a fixed 24-hour scale on the rehaut that encircles the dial. Finally, there is a date at 4:30 that uses white text on a black background. No, I don’t really like the placement or the non-color-matched wheel, but the execution is fairly subtle and quite legible.
With the admitted bias that I’m not personally wild about green-dial watches, I would absolutely opt for the black-dial SPB383 for a somewhat more monochromatic take on the coloring of the dial, the bezel, and the date wheel. Call me boring, but I do love a black-dialed Seiko dive watch, and hey, we carry all three versions in the Hodinkee Shop – so take your pick.
Inside the SPB381, we find Seiko’s new 6R54 movement, which is currently only offered in this trio of Prospex divers. The movement is an automatic that ticks at 21,600 vph and offers both hacking and hand-winding alongside an impressive 72-hour power reserve. This is the first mechanical GMT movement fitted to a Propex dive watch, and the travel function uses an independently set 24-hour hand, making the SPB381 (and its siblings) caller GMTs.
This makes the SPB381 very handy for tracking another time zone from home but less handy for actually traveling and having to adjust the watch to a new local time zone. The caller vs. flyer debate is a fun one, but I own and use examples of both, and there are plenty of use cases where a caller-style GMT function is the ideal option. For the 6R54, the 24-hour hand is adjusted using the first crown position (pull one click out). Rotate one way to advance the date, and rotate the other to advance the GMT hand.
While the SPB381 is not set up like an actual GMT watch (one with a 24-hour bezel), you can easily track a second time zone, and the combination of a dive watch and a second time zone function represents one of my absolute favorite layouts for an everyday sports watch. I loved the dive-GMT format with the Bremont S302 so much that I bought one, so it’s extra easy to love a handsome and considerably less pricy Seiko such as this.
For those of you who worry about the accuracy of Seiko’s movements, the 6R54 is rated for -15 to +25 seconds a day. For kicks, I put this loaner from Seiko on a Weishi 1900 and measured it in six positions with an average of +3.5 seconds per day. While this is just one data point, I was impressed.
As for the touchpoints, the crown is excellent, feeling strong in use and featuring confident threading. The bezel is light and almost silent, with a smooth 120-click action that exhibits no slop but could benefit from a heavier (or more positive) click.
The bracelet is a fully-brushed solid steel affair with solid end links and a fold-over safety clasp. The clasp has four points of micro-adjust and a fold-out wetsuit extension. All told it’s one unit of nicely made and entirely wearable Seiko bracelet, but I would note that the links to a pin-and-collar format, so sizing is a bit more complicated than it would be if Seiko had opted for single-sided screws.
On Wrist
On wrist, the case and bracelet come together really nicely, and, after several days of wear, I think Seiko has managed to take the premium perspective of the Prospex line and make a really solid dive-GMT. Weighing in at 165g (sized for my 7-inch wrist), it wears with a heavy presence that matches the more luxurious look of elements like the polished case band, the applied markers, and the glossy ceramic bezel.
Legibility is excellent, as is the lume, and I didn’t find the SPB381 to be too big, or too thick on my wrist, as the curved lug shape keeps the case in place on your wrist, and the bezel forms the widest edge of the watch (from 3 to 9 o’clock). I’d say that the SPB381 feels like a more solid expression of an SKX007’s footprint. So not a small watch, but also not oversized.
When I first took the SPB381 from its box, I wasn’t sure if it was going to be more like an up-market SKX with a GMT – something many people have asked for, and mostly got with the SSK GMTs last year – or a budget-friendly Prospex take on a flagship Seiko diver. After a few weeks of trying it out, I think it lands firmly in the realm of the latter option with a premium feel and many elements that have been borrowed from much more expensive Seiko (or even Grand Seiko) divers.
If, like me, you lament that Grand Seiko’s dive watches are often quite large, the SPB381 (and it’s siblings) are worth a look just for the combination of aesthetics and proportions. No, the SPB381 isn’t a GS in disguise, but it is a big step up from something like an SKX or even the more industrial finishing of an SPB143.
Competition
If you’ve been rocking an SKX for the past forever and want something that offers more in just about every category while still nailing that Seiko vibe, you have three great new options in the SPB38X GMTs.
But there is one more factor that we haven’t addressed, and that’s the price. I previously mentioned that the competition in the sub-luxury GMT space is hot (and only getting hotter), and that means many buyers have the latitude for additional price sensitivity and/or niche demands. Seiko is offering the SPB381 and SPB383 (that’s green or black, respectively) for $1,500, and I’ve seen (and personally received) feedback claiming that to be too much, especially given the caller-format GMT functionality.
I believe this requires a closer inspection of the competition as the past five years have seen a progressive re-thinking in what we might expect to get from our money when it comes to a mechanical watch with a travel function – flyer, caller, or otherwise.
So, with this Seiko dive-GMT sitting at $1,500, let’s see how it stacks up against a not-exhaustive cross-section of similar competition in the $1000 – $2000 price range. Think flyer or caller gmt with 200 meters of water resistance and, preferably, a Dive-GMT layout.
Here is a hopefully useful list, and though it is presented in no specific order, I’ve included some popular 200m-capable GMTs (“GMT-divers” for simplicity). Otherwise, it would be a very short list—also, a special shout-out to the best Slack crew ever for helping me build out the options.
Hodinkee
