Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchThe Black Bay 58 GMT and the non-GMT Black Bay 58 are both 39 mm METAS Master Chronometer watches. The choice is mainly about function: the GMT adds a second-time-zone display and a 24-hour bidirectional bezel, while the slimmer cited non-GMT reference has a time-only display and a unidirectional dive bezel. Here’s how the current U.S. configurations compare.
Black Bay 58 GMT vs. Black Bay 58: specifications
The comparison below uses TUDOR’s cited U.S. references: M7939G1A0NRU-0001 for the GMT and M7939A1A0NU-0001 for the non-GMT model. Bracelet and strap choices vary across each model range.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Tudor GMT 58 Black Bay | $5,449.98 | Buy on Amazon |
| 2 |
|
TUDOR Black Bay 58 GMT | $5,550.00 | Buy on Amazon |
| 3 |
|
Tudor Heritage Black Bay GMT Stainless Steel Automatic Mens Watch M79830RB-0001 | $4,650.00 | Buy on Amazon |
| 4 |
|
Tudor Black Bay Automatic Black Dial GMT Pepsi Bezel Men's Watch 79830RB-0002 | $4,900.00 | Buy on Amazon |
| 5 |
|
Tudor 58 Black Bay | $4,942.64 | Buy on Amazon |
| Specification | Black Bay 58 GMT | Black Bay 58, non-GMT |
|---|---|---|
| Cited reference | M7939G1A0NRU-0001 | M7939A1A0NU-0001 |
| Movement | MT5450-U, COSC- and METAS-certified | MT5400-U, COSC- and METAS-certified |
| Functions | Hours, minutes, seconds, and integrated GMT with jumping local hour | Hours, minutes, and seconds |
| Bezel | 24-hour, bidirectional | Dive bezel, unidirectional |
| Case diameter | 39 mm | 39 mm |
| Case thickness | 12.8 mm | 11.7 mm |
| Water resistance | 200 m / 660 ft | 200 m / 660 ft |
| Power reserve | 65 hours | 65 hours |
| Bracelet and strap options | Steel bracelet or rubber strap versions are shown | Five-link bracelet, three-link rivet-style bracelet, or rubber strap options are shown across the range |
| TUDOR U.S. suggested retail price for cited reference | $5,525 | $5,225 |
Specifications and listed prices are from TUDOR’s official Black Bay 58 GMT product page and Black Bay 58 product page. Prices are changeable U.S. suggested retail prices, not guaranteed transaction prices; check the current page for the exact reference and configuration.
What the GMT function adds
The GMT reference is the one to consider if you want to track another time zone. Its integrated GMT function works with a 24-hour bidirectional bezel, and the local hour jumps, allowing the local time to be adjusted in hour increments. The non-GMT reference displays hours, minutes, and seconds without a second-time-zone function.
#1 Best Overall
- Tudor Black Bay 58 GMT "Coke" Automatic 39mm Black Dial Men's Watch M7939G1A0NRU-0001
These are different bezel jobs, not simply different colors or styling. The GMT’s 24-hour scale supports reading a second time zone; the non-GMT watch’s unidirectional bezel is the dive-style option. Choose according to the function you expect to use.
Is the Black Bay 58 GMT thicker?
Yes, in the cited references TUDOR lists the GMT at 12.8 mm thick and the non-GMT model at 11.7 mm. That is a 1.1 mm difference on paper. Both have a 39 mm case diameter, so thickness—not diameter—is the measurable case-size distinction in these specifications. The figures apply to the references shown above; they do not establish how either watch will feel on a particular wrist.
Rank #2
- Tudor Black Bay 58 GMT "Coke" Automatic Black Dial Men's Watch M7939G1A0NRU-0002
Are both Black Bay 58 models Master Chronometer certified?
Yes. TUDOR identifies both the GMT and the non-GMT Black Bay 58 as METAS Master Chronometer certified, and both cited movements are also COSC-certified. “Master Chronometer” is not exclusive to the time-only watch.
TUDOR describes the certification as covering precision, resistance to magnetic fields, waterproofness, and power reserve. On the GMT product page, the manufacturer says testing includes two temperatures, six positions, and two power-reserve levels, and specifies resistance to a 15,000-gauss magnetic field. Those are TUDOR’s descriptions of its certification and product, not independent comparative test results.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Rank #3
- 41mm steel case with polished and satin finish
- Bidirectional rotatable bezel in steel with 24-hour graduated anodised aluminium disc
- Self-winding mechanical movement with 70 hour power reserve
Which Black Bay 58 should you choose?
Choose the Black Bay 58 GMT if
- You want an integrated second-time-zone display with a jumping local hour.
- You prefer a 24-hour bidirectional bezel.
- You are comfortable with the cited 12.8 mm thickness and the higher listed U.S. price for the specified reference.
Choose the non-GMT Black Bay 58 if
- You want a straightforward hours-minutes-seconds watch rather than a GMT function.
- You prefer a unidirectional dive bezel.
- The cited 11.7 mm thickness or lower listed U.S. price is more appealing.
Neither choice gives up the shared headline specifications in these cited configurations: 39 mm diameter, 200 m water resistance, 65-hour power reserve, and METAS Master Chronometer certification. TUDOR’s current Black Bay 58 family page presents the range, but exact references determine the configuration and price.
Quick Recap
Best Value
- Main Material: Stainless Steel
- Case Size: 39mm Stainless Steel Case; Lug Width: 20mm; Thickness: 11.7mm
- Series: Black Bay 58
- Dial Hue: Burgundy
- Movement Type: Manufacture Calibre MT5400-U; Self-Winding Mechanical with Bidirectional Rotor
Rank #4
- Tudor Black Bay Automatic Black Dial GMT Pepsi Bezel Men's Watch 79830RB-0002
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
