If you have tried to put a normal strap on your Blancpain x Swatch Scuba Fifty Fathoms and found there was nothing to push, you have not done anything wrong. This watch does not use spring bars.
Instead of two sprung pins you can compress with a fork tool, the Scuba has fixed metal bars that screw into the case from both sides. The factory NATO threads underneath them, which is why the watch ships that way. Anything two-piece — rubber, leather, anything with an end that meets the case — means those bars have to come out first, and a spring bar tool is the wrong instrument for that. Used on this case it will slip, and Bioceramic does not polish out.
This guide covers exactly what you need, the step-by-step, and the two details that catch people out.
First: which kind of strap are you fitting?
There are two completely different answers, and it takes ten seconds to work out which one applies to you.
Pass-through straps — no tools at all. A single-piece NATO, a Zulu, an elastic or any strap that threads under the bars slides straight through. Nothing comes off the watch. This is a 30-second job and the reason the factory chose this construction.
Two-piece straps — the bars must come out. A rubber strap, a leather strap or anything with two separate halves cannot thread under a fixed bar. The bars have to be unscrewed and removed first, and then the strap attaches on its own spring bars.
Most people reading this want the second one, because a two-piece rubber strap is what makes the Scuba look like a dive watch rather than a fashion watch.
What you need
Two hex drivers — one for each side. This is the part nobody mentions. The bar is threaded at both ends, so you hold one side still while you turn the other. One driver is not enough; you need a matched pair, and they have to be the right size for these screw heads.
Our Blancpain x Swatch hex tool set is exactly that — two stainless steel hex drivers sized for the Scuba Fifty Fathoms screw bars. It is the one accessory you genuinely cannot skip on this watch, and it is a buy-once item: fit it now and every future strap change is a two-minute job.
You will also want a soft cloth or a mat to work on. Bioceramic is a ceramic-and-biosourced blend, and while it is tough, a slipped tool leaves a mark you cannot buff away the way you could on steel.
Step by step
- Lay the watch face down on a soft cloth. Work over a tray or a towel — the bars and screws are small and they roll.
- Take a driver in each hand. Seat one in the screw head on the left side of the lug and one on the right. Make sure both are properly engaged before you apply any turning force; that is where cases get scratched.
- Hold one side still and turn the other counter-clockwise. The bar is threaded, so one side effectively acts as the nut. Go slowly. If it binds, back off and re-seat rather than forcing it.
- Lift the bar out and set it aside. Keep both bars and both screws together in a small dish or a zip bag — you will want them if you ever go back to the factory NATO, and they are the easiest part of the watch to lose.
- Repeat on the other lug.
- Fit the new strap on its own spring bars. Your strap comes with spring bars; compress one end, seat it in the drilled lug hole, then walk the other end in until it clicks. The Scuba's lugs are drilled through, which makes this easier than on most watches — you can see and reach the bar from the outside.
- Tug both halves firmly before you wear it. If either side moves, the bar is not fully seated.
Going back to the factory NATO later is the same process in reverse.
The two details that catch people out
It measures 21.7mm — but you order 22mm
The watch press generally lists the Scuba Fifty Fathoms at 22mm. Specialists who have physically fitted straps to it measure the gap at 21.7mm, and they report the same figure consistently across several models in the line.
Order 22mm anyway. A 22mm rubber strap compresses very slightly and seats snugly, which is what you want on a dive watch — that fraction of a millimetre is the difference between a strap that holds and one that rattles. All of our Scuba Fifty Fathoms straps are cut at 22mm for exactly this reason, and the width is stated on every product page rather than hidden behind a selector.
If your strap has built-in quick-release spring bars, take them out first
This is the single most common reason a correctly-sized strap will not go on. Many modern rubber straps ship with quick-release spring bars already fitted into the strap ends — a convenience on most watches, a problem here, because the Scuba's own bars need that same space.
Remove the quick-release bars from the strap and fit plain spring bars instead. Ours are included in the box.
Which strap fits which model
Every Scuba Fifty Fathoms shares the same 42.3mm Bioceramic case, the same 14.4mm height and the same fitting — so any Scuba strap fits any Scuba. If you own two of them, your straps swap freely between them, which is the quiet argument for owning more than one.
The only question is colour. The straps are cut and coloured per model:
- Ocean of Storms — the all-black one. The black FKM rubber strap is the obvious pick and the one that keeps the watch monochrome. If you want a little separation, the black strap with a white LuxLine® adds one raised contrast line and nothing else.
- Atlantic Ocean — the navy FKM rubber strap is the tonal answer, or the navy with a white LuxLine® for a more nautical read.
- Antarctic Ocean · Pacific Ocean · Indian Ocean · Arctic Ocean · Green Abyss — each has its own colour-matched range.
FKM rubber is the right material here. The Fifty Fathoms design exists because of diving, the Scuba is water resistant to fifty fathoms — 91 metres — and FKM handles salt water, chlorine and sun without chalking or going sticky. It is also the material we cover with a lifetime warranty.
Everything is in the Blancpain x Swatch strap collection.
Frequently asked questions
Does the Blancpain x Swatch use spring bars? No. It uses fixed bars that screw into the case from both sides. Pass-through straps thread under them; two-piece straps require removing them.
What tool do I need to change a Blancpain x Swatch strap? Two hex drivers, one for each side of the bar. A standard spring bar tool will not work and risks marking the case.
What lug width is the Scuba Fifty Fathoms? The gap measures about 21.7mm. Order 22mm — that is the size that fits correctly.
Do all the Blancpain x Swatch models take the same strap? Yes. Every model in the collection shares the same case and the same fitting, so straps swap freely between them.
Can I put a rubber strap on it without removing the bars? No. Only pass-through straps go under the bars. Any two-piece strap needs them out first.
Will I damage the watch? Not if you seat both drivers properly before turning and work over a soft surface. The risk is a slipped tool on Bioceramic, not the screws themselves.
Get set up once
The hex set is the only tool you will ever need for this watch, and after the first change the whole job takes about two minutes. Our rubber straps are cut at 22mm specifically for the Scuba Fifty Fathoms and carry a lifetime warranty, shipping is free worldwide with no import costs, and more than 50,000 customers have re-strapped their watches with us.
Shop Blancpain x Swatch straps and tools →
Helvetus is not affiliated with or sponsored by Swatch AG or Blancpain SA. Model names are used for compatibility reference only.
