Longines
HydroConquest L3.780.3.78.9— lug 19mm
Longines HydroConquest L3.780.3.78.9: 19mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.
Artisanal Note
"This model requires a precise 19mm lug width to preserve the original sartorial balance."
Technical Specifications
Longines L3.780.3.78.9The essential strap measurement.
Browse 19mm straps →L3.780.3.78.9
Longines caliber L888.5 Hours, Minutes, Seconds | Date | Chronometer
The Heritage
Compatible Straps
Selected for the 19mm lug width of the HydroConquest
FAQ
What is the lug width of the Longines HydroConquest L3.780.3.78.9?
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).
Which strap is recommended for the Longines HydroConquest L3.780.3.78.9?
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.
How do I change the strap on my Longines HydroConquest L3.780.3.78.9?
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.
Is there an aftermarket strap compatible with the Longines HydroConquest L3.780.3.78.9?
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.
How long does a leather strap last on the Longines HydroConquest L3.780.3.78.9?
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%.