Longines HydroConquest HydroConquest 39 Automatic Stainless Steel / Black / Rubber

Reference L3.780.4.56.9

About this watch

The Longines HydroConquest 39 Automatic is a remarkable watch that beautifully marries style and functionality. From its robust design to its precise movement, it’s a watch that not only tells time but also tells a story—your story. With a striking design and robust functionality, this watch is a true contender in the realm of diving timepieces. The HydroConquest boasts a chronometer certification, ensuring accuracy and precision in its timekeeping. Wearing a watch should feel like a second skin, and the HydroConquest excels in this department with its comfortable fit and adjustable rubber strap. It’s suitable for professional diving activities and offers a contemporary twist on classic diving aesthetics. The Longines caliber L888.5 movement features a silicon balance spring, enhancing precision and reliability.
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Key Features

  • Stainless Steel Case
  • 300m Water Resistance
  • Chronometer Certification
  • Longines Caliber L888.5 Movement
  • Silicon Balance Spring
  • Adjustable Rubber Strap
  • 39mm Diameter

Specifications

Brand
Longines
Family
HydroConquest
Model
HydroConquest 39 Automatic Stainless Steel / Black / Rubber
Reference
L3.780.4.56.9
Movement
l888-5
Movement Features
  • Hours, Minutes, Seconds
  • Date
  • Chronometer
Case
39mm
Dial Color
Black
Crystal
Sapphire
Water Resistance
300

Current Listings

[WTS] Longines Hydroconquest 43mm Full Black Ceramic Ref L3.784.4.56.9 MINT Full Kit $2150

Longines Hydroconquest 43mm Full Black Ceramic Ref L3.784.4.56.9 MINT Full Kit $2150

Longines - L3.784.4.56.9 · $2,150
This Longines HydroConquest features a unique full black ceramic aesthetic, a premium touch with excellent scratch resistance, and a super legible dial in all lighting conditions.

  • Condition: MINT
  • Case diameter: 43mm
  • Thickness: 13mm
  • Lug-to-lug: 56mm
Posted at
Apr 17, 2026, 8:45 PM
Active
[WTS] Longines HydroConquest 39mm Green Ceramic Bezel 2026 NEW L3.779.4.06.6 – $2800 + shipping

Longines HydroConquest 39mm Green Ceramic Bezel 2026 NEW L3.779.4.06.6 – $2800 + shipping

Longines - L3.779.4.06.6 · $2,800
This Longines HydroConquest features a stunning green ceramic bezel and matching dial, with a 39mm size that wears well on the wrist.

  • Condition: Brand new
  • Case Size: 39mm diameter
  • Bezel Material: green ceramic
Posted at
Apr 17, 2026, 6:00 AM
Active
[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