Case #656 — Longines Hydroconquest 41 (Blue) Ref. L3.788.4.96.6

Case #656 — Longines Hydroconquest 41 (Blue) Ref. L3.788.4.96.6

Status: Available
Condition: Excellent Pre-Owned
Scope: Box, Papers, and Cards

🔎 Case Notes

The HydroConquest has long been one of Longines’ most successful modern sports watches. This is the new-generation version, and the changes are more meaningful than a simple dial refresh.

The case has been reworked to 42 mm with a notably slim 11.7 mm profile, the bracelet now incorporates a proper micro-adjustment system, and the blue dial has moved to a rich polished lacquer finish. Paired with a matching ceramic bezel, the result feels cleaner, more refined, and considerably more contemporary than the outgoing HydroConquest.

The blue is particularly good in person. Rather than the flatter tool-watch finish associated with earlier generations, the lacquered dial takes on substantial depth in changing light, while the ceramic bezel keeps the overall appearance crisp and saturated.

And this is a very fresh example.

Case 656 dates from July 2026, presents in excellent pre-owned condition, and includes its box, papers, and cards. The bracelet is currently sized to approximately a 7¾-inch wrist.

As a July 2026 mechanical Longines, it should retain almost the entirety of Longines’ five-year international warranty, subject to the exact purchase date and validity of the completed warranty card.

Longines currently identifies this reference as New, and the brand’s U.S. site is presently showing it as unavailable for immediate online purchase with a “Notify me when available” option—an indication of how quickly this redesigned HydroConquest has attracted attention.

🕰️ The Evidence

• Reference: L3.788.4.96.6
• Model: HydroConquest
• Year: July 2026
• Case: Stainless Steel
• Case Diameter: 42 mm
• Thickness: 11.7 mm
• Lug Width: 21 mm
• Dial: Blue Lacquered, Polished
• Crystal: Sapphire with Multiple Anti-Reflective Coatings on Both Sides
• Bezel: Unidirectional Rotating Ceramic
• Crown: Screw-Down
• Movement: Longines Calibre L888
• Movement Type: Automatic
• Frequency: 25,200 VPH
• Balance Spring: Monocrystalline Silicon
• Power Reserve: Approximately 72 Hours
• Functions: Hours, Minutes, Central Seconds, Date
• Water Resistance: 300 meters / 30 bar
• Bracelet: Stainless Steel
• Clasp: Double-Security Folding Clasp with Micro-Adjustment System
• Bracelet Fit: Approximately 7¾-inch wrist
• Condition: Excellent Pre-Owned
• Factory Warranty: Remaining Longines Five-Year International Warranty, Subject to Warranty Card Date and Terms
• Included: Box, Papers, and Cards

🌟 Collector Provenance

The HydroConquest has occupied an important place in Longines’ catalog because it offers genuine Swiss dive-watch specifications without abandoning the more refined design language associated with the brand.

This latest generation represents one of the more substantial updates to that formula.

The new case proportions are particularly important. At 42 mm across but only 11.7 mm thick, the watch retains substantial dive-watch presence without the visual bulk of many modern 300-meter divers.

Longines also upgraded the bracelet and clasp with a practical micro-adjustment system—exactly the sort of improvement that matters once the watch is actually being worn.

🌟 Design Provenance

The polished lacquer dial changes the personality of the HydroConquest significantly.

Earlier versions leaned harder into conventional tool-watch styling. This new blue dial is deeper and more reflective, particularly when paired with the ceramic bezel.

The result is still unquestionably a sports watch, but one capable of looking considerably more expensive than its position in the market might suggest.

Longines has kept the essential dive-watch ingredients intact: clear luminous markers, strong hand contrast, a unidirectional bezel, screw-down crown, and 300-meter rating.

It simply presents them with more polish.

🧾 From the Case File

This is the kind of generational update that makes a pre-owned example particularly interesting.

A buyer gets the new design, new bracelet/clasp system, 72-hour movement, silicon balance spring, ceramic bezel, and 300-meter capability, but Case 656 has already crossed from new retail into the secondary market.

And barely so.

Dating from July 2026, the watch remains extremely fresh and presents in excellent condition, complete with BPC and most of its five-year factory warranty still ahead of it.

The bracelet is already sized generously at approximately 7¾ inches, and the clasp’s micro-adjustment makes small fit changes considerably easier than on prior generations.

🗝️ BST Verdict

A familiar Longines name, substantially improved.

The newest HydroConquest combines a slimmer 42 mm case, rich lacquered blue dial, ceramic bezel, upgraded bracelet and clasp, 72-hour automatic movement, and serious 300-meter capability.

Add a July 2026 date, excellent condition, full presentation, and nearly the entire factory warranty remaining, and Case 656 offers an unusually compelling alternative to waiting for new inventory to become available.

👉 Every case deserves a closer look.