Longines HydroConquest Hydroconquest Automatic 39 Stainless Steel / Green / Bracelet

Reference L3.779.4.06.6

About this watch

The Longines HydroConquest L3.779.4.06.6 debuted in 2026 as part of the HydroConquest collection, Longines’ line of contemporary dive watches designed for professional water resistance and everyday durability. The model follows the design direction introduced with the HydroConquest GMT in 2024, which revised the collection’s dial layout and finishing. The round stainless steel case is equipped with a screw-in crown and a unidirectional rotating bezel fitted with a ceramic insert. Water resistance is rated to 30 bar. The watch is fitted with a scratch-resistant sapphire crystal with several layers of anti-reflective coating applied to both sides. The dial is finished in green with a polished lacquered surface. Applied indexes serve as hour markers, reflecting the updated HydroConquest design that no longer features Arabic numerals on the dial. Silvered polished hands indicate the time, while a date display completes the functional layout. Power is provided by the Longines calibre L888, a self-winding mechanical movement beating at 25,200 vibrations per hour. The movement is equipped with a monocrystalline silicon balance spring and offers a power reserve of approximately 72 hours. It drives the central hours, minutes, and seconds together with the date indication. The L3.779.4.06.6 is fitted with a stainless steel bracelet secured by a double security folding clasp with a micro-adjustment system.
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Specifications

Brand
Longines
Family
HydroConquest
Model
Hydroconquest Automatic 39 Stainless Steel / Green / Bracelet
Reference
L3.779.4.06.6
Movement
l888-2
Movement Features
  • Hours, Minutes, Seconds
  • Date
Case
39mm
Dial Color
Green
Crystal
Sapphire
Water Resistance
300

Current Listings

[WTS] Longines Conquest 39 mm $600 and Longines HydroConquest 39 mm $700

Longines Conquest 39 mm $600 and Longines HydroConquest 39 mm $700

Two Longines watches for sale, the Conquest L3.776.4 and the HydroConquest L3.741.4.

  • Condition: Very good
  • Case size: 39 mm
  • Year purchased: 2025
  • Clasp wear: minor wear on clasp from being stored at work desk
Posted at
Apr 25, 2026, 1:54 PM
Active
[WTS] Longines HydroConquest 41 – $975

Longines HydroConquest 41 – $975

This Longines HydroConquest 41 features a 41mm case, minimal wear, and comes with its box, papers, hangtag, and warranty card.

  • Condition: Very Good Pre-owned Condition
  • Case Size: 41mm diameter
  • Bracelet Condition: hairlines throughout polished surfaces, some desk wear
Posted at
Apr 25, 2026, 10:32 AM
Active
[WTS] Brand New Longines Hydroconquest Exclusive- 42mm- L3.788.4.98.6

Brand New Longines Hydroconquest Exclusive- 42mm- L3.788.4.98.6

Longines - L3.788.4.98.6 · $2,200
The Longines Hydroconquest Exclusive features a 42mm case with a beautiful frosted blue dial and comes in brand new condition.

  • Condition: Brand new, unworn
  • Case size: 42mm
Posted at
Apr 24, 2026, 6:24 PM
Active
[WTS] New Longines HydroConquest 42mm

New Longines HydroConquest 42mm

A new Longines HydroConquest in the 42mm size, with a mesh band and box and papers included.

  • Condition: New
  • Case Size: 42mm
  • Band Type: mesh
Posted at
Apr 23, 2026, 8:54 AM
Active
[WTS] Longines Hydroconquest Chronograph 41 Ref. L3.783.4 – Travel Box & Manual | $1,850

Longines Hydroconquest Chronograph 41 Ref. L3.783.4 – Travel Box & Manual | $1,850

Longines - L3.783.4 · $1,850
The Longines Hydroconquest Chronograph is a high-performance Swiss diver's watch that features a 41mm case, blue ceramic bezel, and screw-down crown. It houses the calibre L688.2, a column-wheel chronograph movement with a 54-hour power reserve.

  • Condition: Very good with minor usage marks
  • Case Size: 41 x 51mm stainless steel case with a thickness of 15.6mm and a lug width of 21mm
  • Movement: Longines L688.2, automatic column wheel chronograph with 27 jewels, 28,800 bph, and a 54-hour power reserve
  • Water Resistance: 300 (30 ATM)
Posted at
Apr 22, 2026, 3:35 PM
Active
[WTS] Longines HydroConquest GMT 41mm Black, Full Kit, June 2025

Longines HydroConquest GMT 41mm Black, Full Kit, June 2025

Up for sale is my mint condition Longines HydroConquest GMT, a full kit with box, papers, tags, and over 4 years left on the factory warranty.

  • Condition: Mint condition
  • Case dimensions: 41mm diameter, 49mm lug to lug, 12.9mm thickness
  • Movement: L844.5 with 72hrs power reserve
  • Water resistance: 300m
Posted at
Apr 19, 2026, 10:47 PM
Active
Longines HydroConquest, L3.781.4.06.9, Steel Diver, Olive, Excellent Condition.

Longines HydroConquest, L3.781.4.06.9, Steel Diver, Olive, Excellent Condition.

Longines - L3.781.4.06.9 · $1,095
This Longines HydroConquest is a steel diver's watch with an olive green matte dial and a unidirectional rotating ceramic bezel. The stainless steel case measures 41mm in diameter and has a water resistance of up to 300 meters.

  • Condition: Excellent Condition
  • Case Diameter: 41mm
  • Thickness: 11.9mm
  • Bezel Type: Unidirectional rotating Green Ceramic
Posted at
Feb 5, 2025, 2:47 AM
Active