The Tudor Black Bay GMT With White Opaline Dial

The Tudor Black Bay GMT has been with us now for some time, having first been introduced in 2018; its slightly smaller sibling, the Black Bay 58 GMT, was announced just this year. The differences between the two are relatively small but each one has its own distinct personality. And in both instances, you get a sturdy, durable, reliable take on the GMT complication.

GMT watches are less common than diver’s watches but they offer, it seems to me, more practical benefits. Diver’s watches are as we all know, probably the most frequently worn type of mechanical watch, but they seldom actually dive, and without question, there are a lot more people traveling by air than SCUBA diving (in 2023 over 800 million passengers flew domestic in the USA, and that’s just domestic). Whether or not anyone actually needs a GMT complication is as open for discussion as the need for any mechanical wristwatch, but having gone through periods of sometimes very frequent flying, I’ve found it to be the one type of watch I’ve genuinely missed if I didn’t wear it.

I think this has to do with the fact that you can get more or less instantly oriented with respect to time in more than one time zone with a GMT complication – there is something very emotionally steadying about waking up not knowing where you are or what time it is (which has happened to me more than once, both on planes and in hotels) and seeing both local and home time clearly, and instantly.

The GMT complication was like most horological complications, born of necessity. Air travel generally means crossing multiple timezones, and those timezones exist thanks to the invention of national rail networks. The time of day prior to the Industrial Revolution was determined locally but mean solar noon would happen at different times at different locations. A single uniform time system was necessary for practical and safety reasons and so “railway time” was instituted – originally, Greenwich Mean Time was the standard for the British rail system, starting with the Great Western Railway, all the way back in 1840. The system of dividing the world into multiple standard time zones took hold gradually, but by 1929, most countries had adopted time zones with one hour offsets from GMT (although today there are a number of countries and provinces with time zones that are not full hour offsets; Central Australia time is GMT + 8:30).

There are a couple of different ways to do a GMT complication, which have been nicknamed “flyer” and “caller” GMTs (the nicknames were I believe coined by James Stacey). A flyer GMT is one in which the hour hand is used to show local time, and which can be set forwards or backwards in one hour incremements; the GMT hand rotates once every 24 hours and is used to show home time. A caller GMT, on the other hand, has a 24 hour GMT hand which can be independently set – these are more complicated to reset to local time when you travel, since you have to pull out the crown (which stops the watch) set the watch to local time, and then set the GMT hand to home time; this makes such watches more convenient if you are home and need to know the time in a different city – for a business call, for instance. Both the Black Bay GMT and Black Bay 58 GMT are caller GMT watches.

The Black Bay GMT case is exactly the same diameter as the 41mm Tudor Black Bay diver’s watches, and as a matter of fact it shares the same water resistance – 200 meters; which means that the only thing that keeps the BB GMT from being a full-spec diver’s watch is the two way rotating bezel (well, and the absence of a lume pip on the bezel triangle). Certainly if you are using your GMT watch to keep you oriented during air travel, if you are worried about exceeding the depth rating you may have other, more pressing problems). This particular model we have for this edition of A Watch A Week is a fairly recent addition to the Black Bay GMT lineup, with an opaline dial; the model was introduced in 2023.

The bezel, in keeping with tradition (the first Black Bay was the Heritage Diver, and the line has of all Tudor’s product lineup, been the one most visibly connected to some of Tudor’s vintage and heritage models) is anodized aluminum, in a two color “Pepsi” configuration which is impossible to look at without feeling a pleasant twinge of nostalgia. Various two tone GMT watch bezels have been given various nicknames; “Pepsi” of course refers to the red and blue Pepsi logo, but the color difference is functional – it’s there to make it easier to tell the difference between, roughly, day and night (the blue half is numbered from 6PM to 6AM and the red half, vice versa).

The opaline dial Black Bay GMT is relatively subtle in its visible connections with vintage watchmaking, eschewing things like tinted lume, and gilt accents; the snowflake style hour and GMT hands are rooted in vintage Tudor design but they have been part of the current lineup for a dozen years now and are just as much a part of modern as vintage Tudor design language. The bracelet is the other overt appeal to tradition, with its riveted links. “Opaline” in the context of watch dials, means a slight opalescence, almost like the slight luster you get from a fired enamel dial (the latter is not an ideal material for a working travel watch thanks to its tendency to crack).

The case is very well made – very high quality hands, dials and cases are more or less guaranteed from Tudor, and as with its  siblings in Tudor’s GMT collections, finishing is simple, unpretentious, and immaculate, which is proof that it’s much better to do a few things well than a lot of things poorly.

Legibility is excellent. A black dial is slightly easier to read but the difference in tone and texture between the hands and the dial means that telling the time requires no effort at all, and the red GMT hand stands out smartly from its surroundings. Visibility in low light – say, the dimness of an aircraft cabin on a redeye flight – is excellent as well.

At 41mm x 14.6mm this is a slightly larger watch, but the 41mm Black Bays are very comfortable to wear nonetheless – I’ve had a Black Bay diver since 2015 which is also a 41mm and have never found it irksome in size (or weight). There is a certain appeal to the Black Bay’s slab-sided case – the geometry of the case overall and details like the crisp execution of the lug bevels, adds to the feeling of a consistent commitment overall to offering a lot of real value. Added to this is the in-house movement, caliber MT5652, which is COSC certified (unsurprisingly, Tudor watches tend to run better than the minimum chronometer spec of -4/+6 seconds per day; after nine years my own Black Bay diver gains one to two seconds per day.

In some respects, and leaving aside for a moment the riveted bracelet, this feels like the most contemporary of the Black Bay GMT watches (the BB 58 GMT is a more overtly vintage-styled design, with its gilt accents). In fact, in the hand and on the wrist, it makes what I suspect is very much the impression that the very first generation of post-World War II GMT watches might have made back in the era when international jet travel was becoming universal. It’s an instrument – a pragmatic instrument with a pragmatic purpose – but like many really well made tools, its integrity of construction, function and design rises to the level of an aesthetic all its own.

See It Here