The new Tudor Black Bay GMT has a 41mm diameter and a 15mm thick stainless steel case. These dimensions are similar to those of the current Black Bay Divers with in-house calibre.

In comparison the new Black Bay Fifty-Eight is 2mm smaller and 3mm thinner. The case is polished on the sides and has satin finish on top.

The GMT keeps the successful design of the Black Bay divers. The watch has a matte black dial, gold-plated applied round indices, except at 6, and 9 o'clock, where they are rectangular and at 12 o'clock, where is located the traditional Tudor triangular index. A date window is located at 3 o'clock.

The hour, second and GMT hands adopt the famous Tudor snowflake design. The hour, minute and second hands are white-gold-plated, whereas the GMT hand is red painted. The dial is protected by a domed sapphire crystal. The watch is a 200M resistant diver. The watch has a bidirectional rotatable 48 notches bezel in steel with 24-hour graduated anodized aluminum disc in matte burgundy and blue. I insist on the fact that the bezel red is burgundy and its blue is quite dark, it even often appears dark. Those expecting a true Pepsi bezel will be a bit disappointed. The TUDOR rose logo appears in relief on the crown.

The watch is powered by the new in-house calibre MT5652. Tudor did a great job to not increase the size of the Black Bay case. The calibre MT5652 is a native GMT calibre, the GMT feature has not been superimposed onto an independent time-date calibre. The calibre thus features a self-winding mechanical movement with bidirectional rotor system, date and GMT functions. The calibre performances are up-to-date: 70h power reserve and COSC certification.

The watch comes with a (fake riveted) steel bracelet with polished and satin finish with folding clasp and safety catch, a “Terra di Siena” brown leather strap with folding clasp and safety catch or a black fabric strap with burgundy band and buckle. In case you want to replace the bracelet, because this watch looks great with a leather strap and a Nato strap too, the lug width is 22mm.

As usual there is no transparent case back on the Black Bay but a steel one instead. You will thus not be able to look at the new GMT calibre. There is traditionally no need to see the calibre on a diver, and thus no need to spend effort and time to specifically decorate the movement. After all it is a tool watch, not a dress watch.

I however always found it is nice to see the movement, especially to check if every parts are running well inside the watch. It is also useful to check if there is any sign of humidity in the movement (that is the problem with a diver watches, some people take theme into water).

It was quite a surprise when Tudor and Rolex announced during Baselworld 2018 that they were both releasing a GMT Pepsi. A common design feature is that the two watches do not propose a true Pepsi-colored bezel. The Rolex GMT has a purple-pink bezel, whereas the Tudor GMT has dark blue-Burgundy bezel. To my opinion the two watches are not aiming at the same target. The Rolex GMT is aiming at a higher luxury level, whereas the Tudor GMT stays true to the tool-watch roots. I would say that the Tudor GMT looks very much like a retro-inspired Rolex GMT with aluminum bezel instead of the current Rolex GMT ceramic bezel. For those who especially miss the vintage Rolex models, and do not want to jump into the vintage minefield, the Tudor Black Bay GMT is for you. I want to be clear, not only the Rolex nostalgics will love the Tudor watch, everyone who likes GMT tool-watches will love it. The Tudor and Rolex GMT performances are similar. The Tudor design is a homage to the vintage Rolex GMT, and it costs twice less. The Tudor GMT is however a bit bulkier than its Rolex counterpart and does not have the Rolex "wahoo" factor (yet). So is the Tudor GMT the new Rolex GMT killer? It might!

I can not deny that Tudor did a great job when developing this new GMT. No doubt this new Tudor GMT is a fantastic watch. I am in fact convinced that Rolex and Tudor realised that the Tudor GMT would hit the sales of the Rolex, especially when the Rolex GMT is impossible to get in your AD. I think this is the reason why there is also a supply shortage for the Tudor GMT. (I think the same reason applies to the awesome Tudor Black Bay Fifty-Eight). Do I have any suggestion to improve the Tudor GMT? I would love Tudor manage to fit a GMT function in a Black Bay Fifty-Eight case. That would be the new champion on the market. Is it currently possible? Not sure.

One last comment: apparently some of the first Tudor GMT models were suffering of malfunctions with the date feature. This issue has apparently been now solved by Tudor, but if you own this model, better check from time to time before the guaranty expires.