Longines HydroConquest Hydroconquest Chronograph L688

Reference L3.696.4.13.6

About this watch

The Longines Hydroconquest Chronograph L688 is a masterpiece of luxury watchmaking that seamlessly blends functionality, style, and heritage. This Swiss-made timepiece boasts an impressive array of features, including a robust stainless steel case with a silver dial, Arabic numerals, and proprietary hands designed for maximum readability. The rotating bezel, with its 0-60 scale, is a functional piece of art that's perfect for measuring elapsed time while diving or engaging in other time-critical activities. At the heart of this watch lies the Longines caliber L688.2, an automatic movement that offers precision and reliability, with a frequency of 28,800 vibrations per hour and a power reserve of 54 hours. With its impressive water resistance of up to 300 meters, this watch is built to withstand the elements, making it perfect for both land-lovers and divers alike. Its sleek aesthetics and refined elegance make it suitable for any occasion, from casual to formal settings.

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Key Features

Longines caliber L688.2 automatic movement
Rotating bezel with 0-60 scale
Stainless steel case with silver dial
Arabic numerals and proprietary hands
Water resistance up to 300 meters
Sapphire crystal glass
41.00 mm diameter

Specifications

Brand

Longines

Family

HydroConquest

Model

Hydroconquest Chronograph L688

Reference

L3.696.4.13.6

Movement

l688-2

Movement Features

Hours, Minutes, Small Seconds
Date
Chronograph, Column wheel

Case

Stainless Steel 41mm

Dial Color

Silver

Crystal

Sapphire

Water Resistance

300

Current Listings

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

Longines - HydroConquest GMT · $1,980

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

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Longines Hydroconquest 39mm Black MINT

Longines - Hydroconquest 39mm Black · $2,200

A mint condition Longines Hydroconquest 39mm in black with a super comfortable bracelet and excellent bezel action.

Condition: MINT
Bracelet type: Super comfortable bracelet
Clasp type: Excellent on the fly clasp
Bezel action: Great bezel action

Posted at

Apr 19, 2026, 9:12 AM

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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

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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

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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

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[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

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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

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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

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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

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