The Black Bay GMT with its bi-directional 24-hour bezel is the most functional Tudor and the strongest secondary market performer in the Black Bay family outside the BB58.
The Black Bay GMT is Tudor's most technically complete reference and commands the highest secondary prices in the Black Bay lineup outside the limited editions; demand from GMT-function buyers is consistently strong.
The Black Bay GMT (ref. M79830RB-0001) is Tudor's traveler's-GMT, 41mm steel, red/blue 'Pepsi' bezel insert in aluminium, and the in-house MT5652 caliber with an independently-jumping local hour hand. Launched in 2018, it answered the long-standing 'why can't I have a GMT-Master at half the price?' question without compromising on the one specification that matters: the local-hour-jump that makes a GMT useful in actual travel.
Tudor announced the Black Bay GMT at Baselworld 2018, a year that also saw the Pelagos LHD GMT and a renewed focus on Tudor's in-house movement portfolio. The MT5652 caliber is a chronometer-certified GMT with a 70-hour reserve and a true traveler-GMT layout (jumping local hour hand, not the cheaper office-GMT layout where only the 24-hour hand is independent). Bezel-insert variants ship in red/blue ('Pepsi') and a later black/grey ('Earl Grey') and the 'Opaline' silver dial.
The Coke-style red/black bezel is not a factory Black Bay GMT issue.
Common things to check: bezel insert (aluminium, not ceramic, fading and minor scratching are normal on used examples; severe denting is a service item); crown function (the GMT crown layout has three positions, verify the local hour hand jumps independently in position 2 and the date moves in position 1); bracelet (the riveted-style bracelet is the canonical option; rubber, fabric, and aged-leather straps also ship factory, verify the bracelet against the box contents); the MT5652 caliber is robust, but the GMT module adds wear surfaces that benefit from a service every 7-10 years; a heavily-traveled example with no service history should be priced with a service factored in.
MSRP is approximately $4,400 on bracelet; the secondary market through 2024-2026 trades clean full-set examples in the $3,800-$4,500 range, close to MSRP and meaningfully below the GMT-Master 126710BLRO (current retail ~$10,900). The 'Pepsi' configuration is the most-traded variant; the 'Earl Grey' bezel has historically traded at a modest discount and is the value buy within the line. Authorized-dealer allocation has loosened since 2023.
Service is performed by Tudor and competent Rolex/Tudor independents, the same service network as the BB58. Service interval is 7-10 years; cost is moderate (low-four-figures via Tudor). The GMT module is the wear point worth watching on examples that have been in regular use; otherwise the watch is as service-tolerant as any modern Tudor.
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MT5652 in-house movement with bi-directional 24-hour bezel and correct two-tone color split authenticate the Black Bay GMT
| Area | What to check | What is correct | Red flag |
|---|---|---|---|
| movement | MT5652 in-house automatic | "Tudor MT5652" engraved; manufacture movement (not ETA); exhibition caseback standard; 70-hour power reserve; "Tudor" signed; COSC certification optional per variant | ETA 2893 base (incorrect for Black Bay GMT); movement unsigned; power reserve inconsistent with MT5652 specification; no exhibition caseback |
| case | Snowflake hands and GMT-specific 41mm case | 41mm diameter; snowflake hour hand with luminous fill; red or aluminum GMT hand reaching 24-hour scale; "TUDOR" on signed crown; screw-down crown; 200m water resistance | Non-snowflake hour hand; GMT hand not reaching outer bezel scale; incorrect case diameter; crown without Tudor signing |
| crystal |
Editorial estimate. Actual prices vary by condition, date, and box/papers status. Live pricing data is in development.
| Two-tone rotating bezel |
| Bi-directional 24-hour bezel (both directions, unlike dive watches); correct color split at 12/24 position; "AM/PM" or numerical 24-hour scale; aluminum or ceramic insert per variant |
| Uni-directional bezel (dive watch, not GMT); color split at wrong position; incorrect hue on red or grey sector; scale numerals inconsistent with documented variant |
