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Case #685 — Tudor Black Bay 58 GMT “Coke” Ref. M7939G1A0NRU-0001
$4,350.00 USD
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Case #685 — Tudor Black Bay 58 GMT “Coke”
Ref. M7939G1A0NRU-0001
Status: Available
Condition: Excellent Pre-Owned
Scope: Box, Papers, and Cards
Case Notes
The Black Bay 58 GMT takes Tudor’s travel-watch formula and puts it into the proportions collectors had been asking for.
At 39 mm wide and just 12.8 mm thick, it is dramatically more compact than the original Black Bay GMT while retaining full GMT functionality. The defining feature is the bidirectional 24-hour bezel with its black-and-burgundy anodized aluminum insert, quickly earning the watch its enthusiast nickname: “Coke.”
Against the domed black dial, gilt-tone applied markers and hands preserve the warm vintage character of the Black Bay family. The red GMT hand ties directly into the burgundy half of the bezel and allows home time to remain visible while traveling.
Inside is Tudor’s Manufacture Calibre MT5450-U, an integrated GMT movement certified by both COSC and METAS as a Master Chronometer. It provides approximately 65 hours of power reserve and uses a true jumping local-hour hand for easy time-zone changes.
This example dates from 2025 and presents in Excellent Pre-Owned condition. It includes its Box, Papers, and Cards and is currently sized for approximately a 7¾-inch wrist.
As a 2025 example, it retains substantial coverage under Tudor’s five-year transferable guarantee, subject to the exact warranty-card date and Tudor terms.
The Evidence
Reference: M7939G1A0NRU-0001
Model: Black Bay 58 GMT
Year: 2025
Case: Stainless Steel, Polished and Satin Finished
Case Diameter: 39 mm
Case Thickness: 12.8 mm
Lug Width: 20 mm
Dial: Domed Black with Gilt Applied Hour Markers
Crystal: Domed Sapphire
Bezel: Bidirectional 24-Hour Stainless-Steel Bezel with Black and Burgundy Anodized Aluminum Insert
Crown: Screw-Down with Tudor Rose
Movement: Tudor Manufacture Calibre MT5450-U
Movement Type: Automatic Integrated GMT
Certification: COSC and METAS Master Chronometer
Frequency: 28,800 VPH
Jewels: 34
Power Reserve: Approximately 65 Hours
Functions: Hours, Minutes, Central Seconds, GMT, Date, Jumping Local Hour
Water Resistance: 200 meters / 660 feet
Bracelet: Three-Link Rivet-Style Stainless Steel
Clasp: Tudor T-fit
Bracelet Fit: Approximately 7¾-inch Wrist
Condition: Excellent Pre-Owned
Factory Warranty: Remaining Tudor Five-Year Transferable Guarantee, Subject to Exact Card Date
Included: Box, Papers, and Cards
Collector Provenance
The Black Bay 58 GMT matters largely because Tudor solved one of the biggest objections to its earlier GMT: size.
The original Black Bay GMT delivered genuine travel-watch functionality but did so in the thicker full-size Black Bay architecture. The 58 GMT brought the complication into a 39 mm case while still using an integrated manufacture GMT movement.
That required more than simply shrinking the watch.
The MT5450-U was engineered around the compact case and retains a true independently adjustable local-hour hand, date synchronization, 65-hour reserve, and Master Chronometer certification.
The black-and-burgundy bezel gives the reference a visual identity of its own and has naturally picked up the familiar collector nickname “Coke.”
Design Provenance
The watch remains unmistakably part of the Black Bay family.
The domed black dial, gilt-tone details, Snowflake hour hand, aluminum bezel, and rivet-style bracelet all draw on Tudor’s vintage-inspired design vocabulary.
The GMT elements add color without making the dial feel busy.
The burgundy lower half of the bezel gives the watch warmth, while the red GMT hand provides a functional accent against the otherwise black-and-gilt dial.
At 39 mm and 12.8 mm thick, the proportions remain compact enough for daily use and considerably more restrained than many mechanical GMT watches.
Technical Provenance
The MT5450-U is one of Tudor’s most advanced compact movements.
It is certified by both COSC and METAS and provides approximately 65 hours of power reserve.
The local hour hand can be advanced or reversed independently in one-hour increments, with the date synchronized to that adjustment.
That makes it a true travel GMT: local time can be changed after landing without stopping the watch or disturbing home time.
METAS Master Chronometer certification also covers precision, power reserve, water resistance, and resistance to magnetic fields up to 15,000 gauss.
From the Case File
This is one of Tudor’s most complete modern sports-watch packages.
The 39 mm case keeps the watch wearable, while the true GMT architecture, rotating 24-hour bezel, date, 200-meter water resistance, and T-fit clasp give it genuine everyday utility.
Case 685 dates from 2025 and presents in Excellent Pre-Owned condition.
It includes its Box, Papers, and Cards and is currently sized for approximately a 7¾-inch wrist.
Buy with Confidence
BST guarantees the authenticity of every watch we sell and provides a 30-day mechanical performance guarantee under normal use.
Accuracy may vary with age and service history, and water resistance is not guaranteed unless specifically stated and pressure-tested.
BST Verdict
The GMT many Tudor collectors were waiting for.
The 39 mm case, black-and-burgundy “Coke” bezel, true jumping local-hour GMT, T-fit bracelet, 65-hour reserve, and dual COSC/METAS certification make the Black Bay 58 GMT one of Tudor’s strongest current sports watches.
Case 685 adds a 2025 date, Excellent condition, complete BPC presentation, and substantial remaining factory warranty to an already highly versatile reference.
Every case deserves a closer look.