Watch reference library
Tudor Black Bay GMT 79830RB “Pepsi”
In production 2018 to present.
Specifications
- Case size
- 41mm
- Case material
- Stainless steel
- Bezel
- Bidirectional 24-hour, matte blue and burgundy anodized aluminum insert
- Dial
- Black, with an additional 24-hour GMT hand
- Movement
- Tudor manufacture caliber MT5652, automatic, COSC-certified
- Power reserve
- About 70 hours
- Water resistance
- 200 meters
- Crystal
- Domed sapphire
- Bracelet
- Steel, riveted-style links, or Jubilee-style bracelet depending on configuration
The story
Tudor unveiled the Black Bay GMT at Baselworld 2018 as the brand's first dual-time-zone wristwatch, built on the established 41mm Black Bay case platform. The ref. 79830RB uses a matte blue and burgundy two-color aluminum bezel insert, a combination that collectors immediately nicknamed Pepsi after the similarly colored bezel long associated with Rolex's GMT-Master. The watch is powered by the Caliber MT5652, Tudor's first in-house movement built specifically around GMT functionality. It uses a flyer-GMT arrangement, in which the local hour hand can be independently advanced or set backward in one-hour jumps without disturbing the running seconds or the separate 24-hour hand that tracks a second time zone against the bezel. Since its 2018 launch, the Black Bay GMT line has expanded to include other bezel colorways and dial finishes, but the 79830RB with its blue and burgundy Pepsi bezel and black dial remains the reference most associated with the model's introduction.
What to check before you buy
Unlike Rolex's ceramic GMT bezels, the Black Bay GMT uses an anodized aluminum insert, which is more prone to fading or scratching over time and should be inspected closely on a used example. Buyers should also check that the GMT hand and bezel remain properly synchronized, since a hand that has been reset incorrectly at some point can throw off the second time zone reading even though the watch otherwise runs fine. The reference has been offered on both a steel bracelet and, in some releases, a Jubilee-style bracelet, so buyers should confirm which bracelet a specific listing includes.
Buying or selling a 79830RB?
Moda is always buying. Text photos to (605) 521-2821 for a fast offer, or start on the Moda Watches page. For any deal with a stranger, Moda's middleman service inspects the watch before money changes hands.
Common questions
Why is the Black Bay GMT called Pepsi?
Collectors nicknamed it Pepsi because of its blue and burgundy two-color bezel, a combination similar to the one long used on Rolex's GMT-Master, though Tudor does not use the name officially.
Was this Tudor's first GMT watch?
Yes, the Black Bay GMT introduced in 2018 was Tudor's first modern watch with a true GMT, or second time zone, function.
What is a flyer GMT function?
It means the local hour hand can be adjusted forward or backward in one-hour jumps independently, without needing to stop or disturb the minutes, seconds, or the separate 24-hour GMT hand.
Is the Black Bay GMT bezel ceramic or aluminum?
It uses an anodized aluminum insert rather than ceramic, which is a point of difference from comparable GMT watches with ceramic bezels.
What water resistance rating does the 79830RB have?
It is rated to 200 meters, consistent with other Black Bay family watches.