Strap for Hydroconquest 39 Quartz Two Tone White

The lug width of the Longines HydroConquest L3.647.3.16.7 is 19 millimetres. This measurement must be taken internally between the two lugs of the case, from wall to wall. Always verify the reference number on the case back (L3.647.3.16.7) before purchasing an aftermarket strap, as other HydroConquest versions may feature different lug widths (18mm or 20mm).

The best strap depends on your intended use. For daily elegance, we recommend hand-crafted alligator in dark brown or moro tones, which creates a fascinating contrast with the blue sunburst dial. For recreational-formal wear, shell cordovan in vegetable tanning develops a natural patina over time. English vegetable-tanned calfskin represents an ideal compromise between aesthetic appeal and moisture resistance. For frequent diving, a vulcanised rubber or NATO canvas strap remains the most durable choice.

Position your watch on a soft surface with the dial facing downward. Locate the pin that passes through the lug from the case. Using an appropriate tool (a specialised lug removal device or spring bar tool), gently push the pin outward from one side until the lug releases. Repeat on the opposite side. Insert the new strap by aligning the holes with the case pins, then re-insert the pins by sliding the strap into position. Verify that the strap is fully secured before wearing the watch.

Yes, hand-crafted leather straps with 19 millimetre lug width are completely compatible with the HydroConquest L3.647.3.16.7. MilanoStraps offers a collection of 19mm straps customisable in leather, length and stitching thread. The Casati Milano atelier also creates bespoke tailored straps with personal leather selection, 18-month warranty and direct support via WhatsApp.

Leather strap longevity depends on diving frequency and maintenance. With predominantly terrestrial use and rapid drying post-immersion, a quality vegetable-tanned calfskin strap lasts 3-4 years. Shell cordovan, being denser and more resistant, may last 5-6 years. If you frequently submerge your watch, dry the strap within 30 minutes of leaving the water to prevent fermentation. A vulcanised rubber strap resists water indefinitely but requires regular cleaning to maintain aesthetics.