The Tudor Black Bay Pro Polar (reference M79470-0004) makes a compact, high-contrast alternative for an Explorer II fan who wants a fixed 24-hour bezel and a separate reference-time hand. Its 39 mm case is not especially thin at 14.6 mm, and its local-time adjustment works differently from a conventional independently set GMT hand. This is a specification-led take, not a physical hands-on review: the assessment below separates Tudor’s published facts from the design trade-offs they suggest.
What the “Polar” Black Bay Pro is
“Polar” is a useful nickname for the light-dial version of the Black Bay Pro; Tudor’s exact reference is M79470-0004. The opaline dial, black-outlined markers and hands, and yellow 24-hour hand give it a distinctly high-contrast look. Tudor describes those details as supporting legibility, though that is the manufacturer’s design intent rather than an independent visibility test.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Tudor Black Bay Pro Automatic Black Dial Men's Watch M79470-0001 | $4,600.00 | Buy on Amazon |
| 2 |
|
Black Bay Pro Tudor Black Bay Pro | $5,949.99 | Buy on Amazon |
| 3 |
|
Pro Black Bay | $5,500.00 | Buy on Amazon |
| 4 |
|
Tudor Heritage Black Bay GMT Stainless Steel Automatic Mens Watch M79830RB-0001 | $4,650.00 | Buy on Amazon |
| 5 |
|
Tudor GMT 58 Black Bay | $5,449.98 | Buy on Amazon |
The reference pairs that dial with a 39 mm steel case and a fixed, satin-brushed steel bezel graduated for 24 hours. The bezel is part of the time-zone display, not a rotating elapsed-time bezel. The overall idea will feel familiar to an Explorer II admirer: a rugged-looking steel watch, a light dial, a 24-hour scale, and a hand dedicated to reference time. The execution and proportions are Tudor’s own.
How its GMT function works
The yellow hand tracks reference time against the fixed 24-hour bezel. To change the local time, the wearer moves the hour hand independently in one-hour jumps; the date follows local time. That setup is useful when crossing time zones because the local hour can be advanced or moved back without resetting the reference-time hand.
#1 Best Overall
- Tudor Black Bay Pro 39mm Automatic Black Dial Men's Watch M79470-0001
“True GMT” is often used for watches whose local hour hand can be adjusted independently, but the label can obscure the practical distinction between different GMT layouts. Here, the independently jumping hand is the local hour hand, while the yellow 24-hour hand indicates reference time. That is the operation that matters more than the shorthand.
What stands out to an Explorer II fan
Size and thickness
At 39 mm across, the Black Bay Pro is a relatively compact proposition by modern sports-watch standards. Its published thickness is 14.6 mm, however, so diameter alone does not tell the whole fit story. The 20 mm lug width is useful when considering strap options, but comfort and how the watch sits depend on the wearer and should be judged on wrist.
This comparison should not be mistaken for a spec-for-spec verdict against an Explorer II: no official side-by-side Explorer II specification is established here. The grounded point is that the Tudor combines a 39 mm diameter with a notably substantial stated thickness, rather than being simply “small” in every dimension.
Dial contrast and bezel role
The opaline surface, dark outlines around the markers and hands, and yellow GMT hand create a crisp contrast pattern. The fixed steel bezel makes the 24-hour scale immediately available for reading the reference hand. That is a different visual balance from a watch whose defining feature is a rotating bezel: here the bezel supports the second-time-zone display and does not provide a movable timing scale.
Rank #3
- Case Material: Stainless Steel
- Case Size: 39mm Steel Case; Lug Width: 20mm; Thickness: 14.6mm
- Series: Black Bay Pro
- Dial Hue: Opaline
- Movement Type: Manufacture Calibre MT5652 (COSC); Automatic with Bidirectional Rotor
Movement and everyday capability
Tudor lists the automatic Manufacture Calibre MT5652 as COSC-certified, with approximately 70 hours of power reserve. The stated reserve means the watch can run for roughly that long off the wrist when fully wound, subject to real-world conditions. Tudor also specifies 200 m water resistance; that rating is not, by itself, a recommendation for any particular activity or a service schedule.
Specifications at a glance
| Specification | Black Bay Pro Polar M79470-0004 |
|---|---|
| Case diameter | 39 mm (Tudor specification) |
| Case thickness | 14.6 mm (Tudor specification) |
| Lug width | 20 mm (Tudor specification) |
| Bezel | Fixed, 24-hour graduated steel |
| GMT display | Yellow 24-hour reference-time hand; independently jumping local hour hand |
| Movement | Automatic Manufacture Calibre MT5652, COSC-certified |
| Power reserve | Approximately 70 hours (Tudor specification) |
| Water resistance | 200 m (Tudor specification) |
Specifications are from Tudor’s M79470-0004 product page.
Rank #4
- 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
Configurations and displayed prices
Tudor’s Black Bay Pro family page displayed $5,075 for the bracelet configuration and $4,725 for certain strap configurations when accessed in 2026 on the U.S. page. These are changeable displayed prices, not a guarantee of current availability or a universal price across markets. Check the current family page for the configuration and regional price applicable to you.
Quick Recap
Best Value
- Tudor Black Bay 58 GMT "Coke" Automatic 39mm Black Dial Men's Watch M7939G1A0NRU-0001
Who should consider it?
- It may suit you if you want an opaline dial, a fixed 24-hour scale, and a GMT layout that lets you jump the local hour when changing time zones.
- Look closely at fit if case height matters more to you than diameter; 14.6 mm is the published thickness, and an in-person try-on is the meaningful way to judge how it wears.
- Compare the actual operation if you are coming from an Explorer II or another GMT. Confirm which hand adjusts for local time and how the 24-hour reference display is read, rather than relying on a shared “GMT” label.
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.
Free tools Windows power users keep installed
One-click scans. No signup required.
