Longines HydroConquest Hydroconquest Chronograph Tachymeter Black

Reference L3.651.4.56.6

About this watch

The Longines HydroConquest Chronograph Tachymeter Black is a testament to the brand's dedication to creating timepieces that combine functionality, style, and durability. Its striking black dial exudes a sporty yet sophisticated vibe, making it a versatile option for both casual outings and formal events. The watch features a robust movement based on the ETA/Valjoux 7750, boasting a 42-hour power reserve and a frequency of 28,800 vibrations per hour. With its impressive water resistance of 300 meters and sapphire glass protection, this watch is designed to withstand underwater activities while remaining stylish enough for everyday wear. The stainless steel bracelet adds to its luxurious feel, ensuring comfort throughout the day. Whether you're deep-sea diving or just going about your day, you can trust this watch to keep you on schedule. With a diameter of 41.00 mm, it strikes a balance between being prominent on the wrist without feeling bulky.

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Key Features

Longines caliber L667 automatic movement
300m water resistance with sapphire glass protection
Stainless steel case with rotating dive bezel
Black dial with stick and dot indexes
Chronograph function with three sub-dials
42-hour power reserve and 28,800 vibrations per hour
41.00 mm diameter and 21.00 mm lug width

Specifications

Brand

Longines

Family

HydroConquest

Model

Hydroconquest Chronograph Tachymeter Black

Reference

L3.651.4.56.6

Movement

l667

Movement Features

Hours, Minutes, Small Seconds
Date
Chronograph

Case

Stainless Steel 41mm

Dial Color

Black

Crystal

Sapphire

Water Resistance

300

Current Listings

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

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

Longines - Hydroconquest 42 · $2,200

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

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Longines Hydroconquest 43mm Full Black Ceramic Ref L3.784.4.56.9 MINT Full Kit $2500

Longines - L3.784.4.56.9 · $2,500

This Longines HydroConquest features a unique full black ceramic aesthetic with a sleek and stealthy design, while maintaining refined and versatile qualities. The watch boasts excellent scratch resistance, legible dial, and comfortable daily wear.

Condition: MINT
Case diameter: 43mm
Thickness: 13mm
Lug-to-lug length: 56mm

Posted at

Apr 10, 2026, 8:26 PM

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Longines Hydroconquest GMT | 41mm | Sunburst Brown | Excellent Condition

Longines - Hydroconquest GMT · $1,350

This Longines Hydroconquest GMT is a refresh of the well-loved hydroconquest line range, featuring a new quick-adjust bracelet and updated bezel with brown ceramic insert. The sunray dial looks incredible in all lighting conditions, especially when exposed to sunlight.

Condition: Excellent
Case size: 41mm diameter
Lug to lug: 49.2mm
Thickness: 12.8mm

Posted at

Apr 8, 2026, 5:34 PM

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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

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