TUDOR · Black Bay 54
TUDOR Black Bay 54 M79000B-0001: specifications and what to check
The smallest of the family at 37mm and 11.2mm, with a bezel insert that carries no minute graduations at all. A period detail that changes how the watch reads and how it must be described.
Reference M79000B-0001 · specifications read from the manufacturer on 2026-09-22 · listed as current
Specifications
As published by TUDOR. A field the manufacturer does not state is left out rather than filled in.
- Case
- 37mm stainless steel case with polished and satin finish
- Diameter
- 37 mm
- Thickness
- 11.2 mm
- Lug width
- 20 mm
- Water resistance
- Waterproof to 200m (660 ft)
- Crystal
- Domed sapphire crystal
- Bezel
- 60-minute unidirectional bezel in stainless steel with aluminium insert devoid of minute graduations
- Dial
- Blue, domed, with applied hour markers
- Crown
- Stainless steel screw-down crown with the TUDOR rose in relief
- Bracelet
- 3-link stainless steel bracelet with polished and satin finish
- Clasp
- TUDOR "T-fit" clasp
Movement
- Calibre
- Manufacture Calibre MT5400
- Type
- Self-winding mechanical movement with bidirectional rotor system
- Power reserve
- Power reserve of approximately 70 hours
- Certification
- COSC
- Notes
- Chronometer certified. Note this is the COSC calibre rather than the METAS-certified MT5400-U used elsewhere in the family.
What to check before you buy
- Read the bezel insert carefully: TUDOR states it is devoid of minute graduations. An insert showing minute markings is not the one this reference ships with, and that is a substitution worth understanding before you buy.
- Check which MT5400 is fitted. This reference is specified with the COSC calibre, not the Master Chronometer variant, and conflating the two overstates what you are selling.
- Assess the case for over-polishing. At 37mm the lugs are slim to begin with, and an aggressive refinish shows on this size far sooner than on a larger watch.
- Confirm the dial is the blue version and that its tone matches under daylight rather than showroom light — domed dials shift noticeably by angle and source.
- Try it on a wrist before you commit stock. Demand at 37mm is real but narrower than at 39 or 41, and the resale audience is different rather than simply smaller.
The bezel is the story
Most dive bezels carry a graduated scale for the first fifteen minutes, or a full sixty. This one carries none — TUDOR specifies the aluminium insert as devoid of minute graduations, which is a faithful nod to the mid-century reference the watch draws its name from.
It is also the single most important thing to get right when describing it. A buyer who knows the reference expects a blank insert; a buyer who does not may assume the watch is missing something. And an insert showing graduations means the part has been swapped, which is a very different conversation about originality.
Smaller again
At 37mm across and 11.2mm deep, this sits below the 39mm Black Bay 58 and well below the 41. Those half-millimetres matter more than they sound: each step down in this family reaches a distinct buyer, and they do not substitute for one another.
Stock it because you have that buyer, not because it is the same watch in another size.
A different certification
The movement here is the MT5400 certified by COSC, not the Master Chronometer MT5400-U found on other references in the range. Chronometer certification is a real standard and there is nothing wrong with it — but METAS certification adds magnetic-resistance and waterproofness testing on top, and the two should not be described interchangeably.
If a listing claims Master Chronometer for this reference, that claim is wrong, and correcting it before the sale is considerably cheaper than afterwards.
Polishing shows here first
Slim lugs on a small case leave very little material to work with. A watch that has been refinished once too often loses its edges, and at this diameter the result is visible across a room to anyone who handles these regularly.
Inspect the lug chamfers under raking light and price accordingly. It is one of the few faults that cannot be undone.
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Sources
Not affiliated with TUDOR. Specifications are read from the manufacturer's own published documentation on the date shown and may change; the manufacturer's current documentation governs.