Longines HydroConquest Hydroconquest Automatic 39 Stainless Steel / Black / Mesh

Reference L3.779.4.70.6

About this watch

The Longines HydroConquest L3.779.4.70.6 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 presented here in a grey tone. 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 black 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 L3.779.4.70.6 is fitted with a stainless steel bracelet in a Milanese mesh style, secured by a double security folding clasp with a micro-adjustment system.
Buy Now on Jomashop
This is an affiliate link

Specifications

Brand
Longines
Family
HydroConquest
Model
Hydroconquest Automatic 39 Stainless Steel / Black / Mesh
Reference
L3.779.4.70.6
Movement
l888-2
Movement Features
  • Hours, Minutes, Seconds
  • Date
Case
39mm
Dial Color
Black
Crystal
Sapphire
Water Resistance
300

Current Listings

[WTS] 2026 Longines Hydroconquest 39mm - Grey Bezel / Black Dial

2026 Longines Hydroconquest 39mm - Grey Bezel / Black Dial

Longines - L3-779-4-70-6 · $2,100
This 2026 Longines Hydroconquest is a 39mm grey bezel/black dial watch, purchased directly from Longines and regularly worn. It's free of major scratches or dents but has minor wear on the back of one lug.

  • Condition: Excellent to LNIB (like new in box)
  • Bracelet length: up to an 8in wrist
  • Bent link pin: one link pin is bent and unusable
  • Included accessories: all original packaging, accessories, and paperwork
Posted at
Apr 16, 2026, 3:09 PM
Active
[WTS] Longines HydroConquest Sunray Blue- L3.790.4.96.6

Longines HydroConquest Sunray Blue- L3.790.4.96.6

Longines - L3.790.4.96.6 · $2,900
A brand new Longines HydroConquest with sunray blue dial, featuring a new box and papers.

  • Condition: Brand new
  • Box And Papers: brand new
Posted at
Apr 16, 2026, 12:11 PM
Active
[WTS] Longines HydroConquest GMT - Unworn, Full Set, Black Dial 41mm. The watch is in completely unworn condition and comes as a full set including box, papers, and all original accessories. Price:1700. UK-based. Happy to ship or meet depending on location. Dm if interested

Longines HydroConquest GMT - Unworn, Full Set, Black Dial 41mm. The watch is in completely unworn condition and comes as a full set including box, papers, and all original accessories. Price:1700. UK-based. Happy to ship or meet depending on location. Dm if interested

The Longines HydroConquest GMT is a 41mm timepiece that comes as a full set including box, papers, and all original accessories. It is in completely unworn condition.

  • Condition: Unworn
  • Case Size: 41mm
  • Set: Full set including box, papers, and all original accessories
Posted at
Apr 16, 2026, 11:26 AM
Active
[WTS] Longines Hydroconquest GMT 41mm Black (Nov 2024)- $2950 AUD (Sydney, Australia)

Longines Hydroconquest GMT 41mm Black (Nov 2024)- $2950 AUD (Sydney, Australia)

Longines - L3.826.4.53.2 · $2,950
a black Longines Hydroconquest GMT watch with a 41mm case size.

  • Material: Stainless Steel
  • Diameter: 41mm
  • Depth rating: 300m
Posted at
Apr 16, 2026, 9:54 AM
Active
[WTS] Longines HydroConquest 41mm

Longines HydroConquest 41mm

Longines - L3.781.4.96.6 · $1,100
A Longines HydroConquest 41mm watch with a blue sunburst dial, featuring a clean crystal and flawless dial.

  • Condition: Excellent pre-owned condition
  • Diameter: 41mm
Posted at
Apr 15, 2026, 3:43 PM
Active
[WTS] Longines Hydroconquest Chronograph 41 Ref. L3.783.4 – Travel Box & Manual | $1,900

Longines Hydroconquest Chronograph 41 Ref. L3.783.4 – Travel Box & Manual | $1,900

Longines - L3.783.4 · $1,900
This Longines Hydroconquest Chronograph is a high-performance Swiss diver's watch featuring a blue ceramic bezel and screw-down crown, powered by the calibre L688.2 column-wheel chronograph movement with a 54-hour power reserve.

  • Condition: Very good with minor usage marks
  • Case Size: 41mm x 51mm stainless steel case, 15.6mm thickness, 21mm lug width
  • Movement: Longines L688.2 automatic column wheel chronograph with 27 jewels, 28,800 bph, and a 54-hour power reserve
  • Water Resistance: 300m (30 ATM)
Posted at
Apr 15, 2026, 11:30 AM
Active
[WTS] Longines HydroConquest GMT Black. Ref: L3.790.4.56.6 (2025) Complete. $1,950

Longines HydroConquest GMT Black. Ref: L3.790.4.56.6 (2025) Complete. $1,950

Longines - L3.790.4.56.6 · $1,950
This Longines HydroConquest GMT Black is a modern dive watch with excellent everyday wearability, offering both tool watch functionality and travel convenience.

  • Condition: Excellent pre-owned
  • Case size: 41mm diameter
  • Water resistance: 300m
Posted at
Apr 14, 2026, 9:45 PM
Active
[WTS] (Longines) (2026 Hydroconquest 42) Full 5 Year Warranty, LNIB

(Longines) (2026 Hydroconquest 42) Full 5 Year Warranty, LNIB

This newly released Longines Hydroconquest is a large watch with exceptional fit and finish. It comes in its original packaging with a full kit and warranty.

  • Condition: LNIB (Like New In Box)
  • Case size: 42mm
  • Water resistance: not specified
Posted at
Apr 13, 2026, 2:48 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