Tudor added blue to the Black Bay 54 in 2026, and it is the version people have been asking for since the model launched. Same 37mm case, same clean bezel, same no-date dial — just a saturated "Tudor blue" across the dial and the bezel insert.
It is also the Black Bay where the obvious strap choice is the one that does not work, and there is a specific reason for that. First, the fit, because there are now two blue 54s and people mix them up.
Strap size and fit guide
Your Tudor Black Bay 54 Blue (Ref. M79000B) has a 37mm case and a 20mm lug width. It shares the exact case with the black-dial 79000N — 37mm across, 11.24mm thick, 46mm lug to lug.
On Helvetus product pages, select "Black Bay 54".
And if you have read that the Black Bay 54 is 19mm, that is wrong. It gets repeated on a few strap sites and it costs people an order. Tudor states 20mm, and every hands-on measurement agrees.
Which blue 54 do you actually own?
There are two, they came out close together, and they need different advice. The fit is identical — 37mm, 20mm, select "Black Bay 54" for either — but the colour logic is not.
| Black Bay 54 Blue (79000B) | Black Bay 54 "Lagoon Blue" | |
|---|---|---|
| Bezel insert | Blue anodised aluminium | Mirror-polished steel, no colour |
| Dial | Sunray-brushed Tudor blue | Sand-textured, lighter blue |
| Bracelet | 3-link | 5-link |
If your bezel is blue, this is your guide. If your bezel is a polished steel mirror, you have the Lagoon Blue, and the advice there is different because that watch has no coloured bezel to work with.
Checklist for this one: 37mm case, 20mm lugs, blue bezel, select "Black Bay 54".
Why you should not try to match the blue
This is the thing worth knowing before you spend anything.
The 79000B has two blues, and only one of them holds still.
The bezel insert is anodised aluminium. It is a flat, consistent colour that looks the same in every light — that is what anodising does.
The dial is sunray-brushed, which is the opposite. It throws light in a band as your wrist moves, so it runs from a vivid, saturated blue in direct light, through a deeper navy, and — as people who have handled it keep noting — occasionally reads almost purple at certain angles. In a dim room it goes close to black.
So when you look at a photo of this watch and think "I'll get a blue strap to match", you are matching one frame of something that never stays still. Match the bezel and the dial will drift away from it half the day. Match the dial and you have matched a colour it only wears some of the time.
The answer is not to match at all. A neutral strap lets the dial run its whole range and every version of it looks deliberate. A deliberate contrast does the same thing from the other direction. What does not work is the near-miss — a blue strap that agrees with the watch at one angle and looks slightly off at every other one. On a 37mm watch where the strap takes up a big share of what you see, that near-miss is very visible.
There is a second reason a strap earns its place here. The 54 has the widest strap-to-case ratio in the Black Bay range — a full 20mm of strap on a 37mm case, where the Black Bay 41 gets 22mm on 41mm. Tudor kept the strap width and shrank everything else, so on this watch the strap is closer to half of what you actually see.
The best strap colours for the Black Bay 54 Blue
Black — the hero, and it is the one that lets the blue perform. Black adds nothing and takes nothing away, which is exactly what a dial like this needs. Every state the sunray finish moves through — vivid, navy, near-black — reads as intentional against black rubber, because there is no second colour telling your eye what the blue is supposed to be. It also makes the blue bezel look more saturated than it does on the steel bracelet, where the surrounding metal washes it out. Safest choice here and genuinely the best-looking one. Black Tudor Black Bay Rubber Strap
Bordeaux — the pairing Tudor uses itself. Blue and burgundy is not an experiment at this brand — it is the colour combination on the bezel of the Black Bay GMT, one of the most recognisable watches Tudor makes. Bringing it to a fully blue watch works for the same reason it works there: burgundy is dark enough not to shout and warm enough to make the blue read as a colour rather than as a shade of dark. This is the strap that makes people ask what the watch is, and it is the most interesting-looking of the four by some distance. Bordeaux Tudor Black Bay Rubber Strap
White — the summer one. Maximum contrast, and on a saturated blue dial that is a good thing rather than a loud one. White pushes the blue forward instead of competing with it, picks up the luminous markers, and turns a fairly serious little dive watch into something you would wear on holiday without a second thought. It is also the strap that makes 37mm look its best on a smaller wrist, because the bright band gives the case a clean edge to stop at. White Tudor Black Bay Rubber Strap
Black with Blue Line LuxLine® — the upgrade, and the one blue that works. If you do want blue on the strap, this is how to do it. A thin, constant blue line against a black body gives you one fixed reference point instead of a whole strap trying and failing to match a dial that keeps changing. The line reads clearly against the black, it ties to the bezel rather than the dial, and the effect is a watch that looks specified rather than assembled. It is also the option that looks sharpest under a cuff. Black w/Blue Line LuxLine® Tudor Black Bay Strap
Full colour range for this case: All Tudor Black Bay Straps
Getting the order right
Colour first, then select "Black Bay 54". Not "Black Bay 58", which is a different case even though it is also 20mm. Not "Black Bay 36", which is 19mm.
If you own other Tudors, or you are cross-shopping:
- Tudor Black Bay Fifty-Eight Navy Blue 79030B Strap Guide — the closest relative, blue dial and blue bezel at 39mm and 20mm
- Tudor Black Bay Fifty-Eight 79030N Strap Guide — 39mm, 20mm, different selection
- Tudor Black Bay 36 Ref. 79640 Strap Guide — 36mm, 19mm
FAQ
What lug width is the Tudor Black Bay 54 Blue? 20mm, on a 37mm case — the same as the black-dial 79000N. The 19mm figure you may have seen on some strap sites is incorrect.
Is the Black Bay 54 Blue the same as the Lagoon Blue? No. The 79000B has a blue anodised aluminium bezel insert, a sunray-brushed dial and a three-link bracelet. The Lagoon Blue has a mirror-polished steel bezel with no colour, a sand-textured dial and a five-link bracelet. Same case and same 20mm strap, different watches.
Should I put a blue strap on a blue watch? Not a plain one. The dial is sunray-brushed and shifts through several blues as the light changes, while the bezel is a constant anodised blue, so a matching strap only agrees with the watch some of the time. A neutral strap, or a black strap with a thin blue line, avoids the problem entirely.
Does the Black Bay 54 come on rubber from Tudor? Tudor offers the 54 on a steel bracelet or a black rubber strap with the T-fit clasp, so rubber is a factory configuration for this model.
Which is the safest first strap? Black. It works with every state of the dial and it makes the blue bezel look richer than it does against steel.
Final thoughts
The 54 was already the most wearable Black Bay, and the blue is the version that makes it feel like a colour choice rather than a default. A strap is what lets that colour actually behave — lighter than the bracelet, better on a smaller wrist, and without the surrounding steel flattening the dial out.
Helvetus straps are cut for this exact case, so you get a clean fit at the lugs with no gaps. Every rubber strap carries a lifetime warranty, shipping is free worldwide with no import costs, and more than 50,000 customers have already made the swap.
