Rubber Straps for the Fifty Fathoms: The Everyday Default
Every Scuba Fifty Fathoms leaves the shop on rubber, and the factory had good reason. It is the only material that copes with everything this watch was designed for — salt water, chlorine, sweat, sun cream, a shower without thinking about it — and dries in the time it takes to make coffee. Rubber is also the category with the widest quality spread in our range of straps for the Fifty Fathoms, which is why two bands that look identical online behave completely differently after a fortnight. What follows is what separates them.
Why rubber is the default and not the compromise
It is indifferent to the things that destroy other straps
Leather is ruined by soaking, canvas holds salt in the weave and takes hours to dry, nylon copes well but lifts the case off the wrist. Rubber absorbs no water at all, so salt sits on the surface and rinses away rather than working into the material, and chlorine and sun cream come off with a little soap. On a watch rated to 9.1 bar that matters, because the case will happily go places most strap materials should not.
It solves a problem specific to this watch
Bioceramic is a fraction of the density of steel, and at 42.3mm across and 14.4mm deep the Fifty Fathoms weighs far less than it looks as though it should. A light watch on a stiff strap wanders: it rotates towards the underside of your wrist over the course of a morning. Rubber conforms most closely to the wrist without adding bulk, so the case stays where you put it — a comfort argument rather than a durability one, and the reason most owners who experiment with other materials eventually come back.
FKM, silicone and the difference you pay for
FKM fluoroelastomer
FKM is the material used for serious dive straps and the one worth the extra money. It is chemically stable, so it resists oils, sun cream and UV without softening; it holds its shape rather than going slack; and it has a dry, matte feel that does not cling to skin. It also attracts far less dust than cheaper rubber, which on a black strap is the difference between looking clean and looking neglected. Expect a good FKM band to cost between €35 and €60, and to outlast three silicone ones.
Silicone
Silicone is softer, cheaper and perfectly usable. Its weaknesses are predictable: it attracts lint, goes slack faster in heat, and turns slightly tacky as it ages. For a spare kept for the pool, or a colour you want to try without committing, it is sensible enough. For the band that lives on the watch, FKM repays the difference within a season.
The ones to be wary of
Unspecified “rubber” at the bottom of the market is usually TPU or a blend with plasticisers that migrate out over time. The symptom is a strap that feels greasy after a few months, then stiffens and cracks at the lug end. You cannot see it in a photograph, but you can smell it on arrival: a strong chemical odour that survives a wash is a reliable warning.
Profile: perforated, ribbed, smooth or tropic
The material decides how long a strap lasts. The profile decides whether you enjoy wearing it. Perforated bands let air reach the skin, which is the single biggest factor in hot-weather comfort: a solid strap traps a film of sweat that never dries while the watch is on, and that trapped moisture causes nearly every complaint about irritation and odour. Ribbed and grooved patterns do something similar by breaking contact with the skin, and hide surface marks better than a flat finish.
Smooth rubber is the dressiest option and the warmest: it suits the darker editions, but avoid it if you sweat heavily or live somewhere humid. Tropic-style patterns sit between the two and are the safest all-rounder. Whichever profile you choose, the measurement that matters is thickness at the lug: 3mm to 4.5mm keeps the proportions right under a 14.4mm case, and anything thicker pushes the stack high enough to catch on a cuff. Our rubber straps for the Fifty Fathoms are cut to the 22mm fitting and the screw bar hardware this case uses, which removes the most common source of trouble with a generic band.
Fitting: the part where people damage the case
The Fifty Fathoms uses screw bars rather than spring bars, so changing a strap needs two 0.9mm hex drivers and five unhurried minutes. It is not difficult, but it is the moment at which most damage happens. Work on a soft cloth, support the watch so it cannot slide, and keep the driver square in the screw head — a driver that cams out leaves a mark on bioceramic that no polishing will remove. Ease the new strap end into the lug gap rather than forcing it, and tighten the caps firmly without overtightening the thread.
One thing owners routinely forget: the screw bar caps loosen over months of wear and vibration, particularly if the watch swims regularly. Check them with a driver every couple of months rather than discovering the problem the hard way.
Buckle, keepers and the parts that fail first
Straps rarely fail in the middle. They fail at the buckle, where the tang wears the holes oval, and at the keepers. Look for a brushed 316L stainless steel buckle rather than plated base metal — plating looks identical in a photograph and starts pitting within a summer of sea water. Closely spaced holes matter more here than on most watches, because your wrist swells in heat and shrinks in cold water, and a half-step adjustment is often the difference between correct and irritating.
A slack keeper is the usual reason a strap looks untidy, not the strap itself, and a replacement costs a fraction of a new band. Integrated moulded keepers cannot go slack, but cannot be replaced when they tear either.
Care, which takes about thirty seconds
Rinse the strap under cold fresh water after every sea swim, buckle open, working the water through the perforations. Salt dries into fine abrasive crystals that grind at the material every time the strap flexes, and that is what ages a rubber band rather than the water itself. Once a fortnight, wash it properly: lukewarm water, one drop of mild washing-up liquid, a soft toothbrush along the edges and around the buckle holes, then rinse thoroughly — leftover soap is what makes a clean strap feel tacky.
Two things to avoid: drying a strap on a radiator, in a car or in direct sun, since heat above about 40°C softens rubber and deforms it at the lug ends; and alcohol gel or antibacterial wipes, which strip the plasticisers and leave the surface chalky. A pale band that has picked up denim dye responds well to a thin paste of bicarbonate of soda, applied with a toothbrush and rinsed off after two minutes.
Colour across the ocean editions
Every edition arrives with a dial and bezel already doing the talking, which makes rubber straightforward: go quieter than the watch, or match it exactly. The two approaches that work are a neutral — black, grey, navy — which lets the bezel be the point, or a deliberate colour match that leans into the watch’s cheerfulness. What rarely works is a near miss: an orange strap almost but not quite the orange of the bezel reads as a mistake rather than a choice. Because the case dimensions and fitting are identical across the range, one strap moves freely between editions. The best-selling bands are overwhelmingly neutral for exactly this reason.
Frequently asked questions
What size rubber strap does the Scuba Fifty Fathoms take?
22mm at the lugs. A taper to 20mm at the buckle keeps the wrist end tidy without changing how the strap looks at the case.
Is FKM really worth paying more for than silicone?
For the strap you wear daily, yes. It resists oils and UV, stays taut rather than going slack, and does not attract dust. For a spare kept for the pool, silicone is fine.
Can I shower and swim in a rubber strap?
Yes, and it is the material best suited to both. Rinse it in fresh water after the sea so salt does not stay in the perforations.
Why has my rubber strap gone sticky?
Usually leftover soap, or plasticisers migrating out of a cheap compound. Wash and rinse it twice; if it is still tacky, the material is breaking down and the band is done.
How long should a good rubber strap last?
A well-made FKM band will take two to three years of daily wear. Oval buckle holes and a slack keeper are the usual first signs of age.
The strap that asks least of you
Leather gives this watch a second personality, a bracelet gives it weight, nylon gives it security. Rubber gives it none of those things, and it will still spend most of the year on the watch, because it is the only band you never have to think about before doing something. Buy FKM rather than an unspecified compound, choose a perforated or ribbed profile if you wear the watch in heat, keep the thickness between 3mm and 4.5mm, insist on a steel buckle with closely spaced holes, and rinse it after the sea. A strap that meets that specification will still look right long after the fashionable alternative in the drawer has been quietly retired.
Also read our previous article: Summer Straps for the MoonSwatch: What to Wear from June to September