Strap for Fifty Fathoms Bathyscaphe Stainless Steel / Blue / Blue Canvas

The lug width of reference 5100-1140-O52A is precisely 20mm. This measurement is determined by the internal distance between the two lugs (the small metal cylinders through which the strap passes). When verifying compatibility with an aftermarket strap, always measure this internal distance, as even minor variations (±0.5mm) affect the final fit.

The choice depends on usage and context. For formal and daily wear, black alligator is the classic standard. If you seek versatility and character, vegetable-tanned veal with a medium grain offers a sporty yet refined texture. For water activities or summer use, an FKM rubber strap maintains technical protection without the risk of leather degradation. Shell cordovan, for those preferring extreme resilience and luminous patina development over time, represents a lasting investment.

Strap replacement requires a spring bar tool and a protected flat surface. Locate the small lateral holes at the case ends where the spring bar pins are anchored. Gently insert the spring bar tool into the hole and apply light pressure to compress the internal spring, extracting the old pin. Repeat on the other side. Install the new strap by inserting one end of the spring bar into the first lug, then compress and insert the other end into the second lug. If unfamiliar with the procedure, consult a professional watchmaker.

Yes. Any strap with a 20mm lug width is dimensionally compatible. However, note that not all 20mm straps offer the same construction quality or aesthetic finish. Bespoke straps crafted by specialised ateliers (such as Casati Milano) guarantee careful tanning, symmetrical topstitching, and stainless steel lugs of superior quality. Always verify that the strap has been tested on watches of comparable calibre: Rolex Submariner, Omega Seamaster, and Tudor Black Bay share similar lug specifications.

Longevity depends on material, tanning method, and maintenance. An alligator strap with vegetable tanning, worn daily, maintains structural integrity for 3–5 years before requiring restoration or replacement. Shell cordovan, thanks to fibre density, can last 8–10 years or beyond. FKM rubber straps are indefinitely resistant if protected from prolonged direct sunlight. To extend lifespan, avoid prolonged immersion in fresh water (fibre swelling weakens adhesives), always dry the strap after saltwater contact, and apply natural wax conditioner every six months.