Longines HydroConquest Hydroconquest Chronograph

Reference L3.644.4.56.6

About this watch

The Longines Hydroconquest Chronograph L3.644.4.56.6 is a stunning combination of style, functionality, and reliability. With its robust build, it promises durability while ensuring that you look good whether you’re at the beach or in a boardroom meeting. The case is made from high-quality stainless steel, creating a balanced presence on the wrist. The black dial features mixed indexes providing a sporty vibe while ensuring easy readability. The chronograph sub-dials are well-placed, making it simple to track time in various ways. At the core of this watch is the renowned ETA caliber 7750 automatic movement, celebrated for its reliability and precision. The sapphire glass ensures that the watch remains clear and legible no matter the conditions you put it through. With a water resistance rating of 300 meters, the Hydroconquest Chronograph is more than just a pretty face; it's a true diving companion.

Buy Now on Jomashop

This is an affiliate link

Key Features

41mm diameter stainless steel case
Sapphire glass for scratch resistance
Renowned ETA caliber 7750 automatic movement
Chronograph feature with easy-to-read sub-dials
Water resistance of up to 300 meters
Robust and durable design
Proprietary hands for a unique touch

Specifications

Brand

Longines

Family

HydroConquest

Model

Hydroconquest Chronograph

Reference

L3.644.4.56.6

Movement

7750

Movement Features

Hours, Minutes, Small Seconds
Date, Day
Chronograph

Case

Stainless Steel 41mm

Dial Color

Black

Crystal

Sapphire

Water Resistance

300

Current Listings

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

[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

Longines - HydroConquest GMT · $1,700

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange

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

View listing on r/WatchExchange