Strap for HydroConquest 39 Automatic Stainless Steel - Pink Gold / Grey / Rubber

The lug width of the Longines HydroConquest L3.780.3.78.9 is 19 mm, the standard for Longines sports and diving models. This measurement is not interchangeable: a 18 or 20 mm strap would result in aesthetic defects (misaligned lugs) and functional issues (slipping during diving).

For elegant daily wear, an alligator in vegetable tanning with petrol blue or cognac brown tones creates contrast. For actual diving, rubber or NATO resist saltwater corrosion. For versatile styling, shell cordovan offers density and natural patina with refined aesthetics. A stainless steel deployant clasp complements any choice, enabling rapid strap changes.

Obtain a pin remover tool or hand drill. Position the watch on a soft cloth, identify the two axes connecting the strap to the case lugs, and remove them by applying firm, consistent pressure from outside inward. Align the new 19 mm strap and reinsert the axes using the same method. If uncertain, consult a professional watchmaker.

Yes. Any strap with a 19 mm lug width is compatible. Specialist suppliers offer straps in alligator, vegetable-tanned calf, shell cordovan, and technical rubber, all custom-made for this width. We recommend artisans who guarantee material quality and construction precision, avoiding generic products that compromise the watch's appearance and comfort.

A quality leather strap (alligator, vegetable-tanned calf, shell cordovan from established producers) lasts 3-5 years with moderate daily use, thanks to natural tanning that allows elasticity and breathability. Frequent water exposure (regular diving) reduces lifespan to 1-2 years: rubber or NATO are preferable. Maintenance (gentle cleaning, post-immersion drying) extends usable life by at least 50%.