Longines HydroConquest Hydroconquest Chronograph L688

Reference L3.696.4.53.6

About this watch

The Longines Hydroconquest Chronograph L688 is a statement piece that combines elegance with functionality. This robust diving watch features a stunning black dial, Arabic numeral indexes, and a rotating bezel for precise timing. Its 300-meter water resistance makes it perfect for underwater escapades. The automatic movement, powered by a column wheel chronograph system, ensures smooth and accurate operation. With a 54-hour power reserve, you can wear this watch without worrying about winding it every day. The stainless steel case is durable and polished, making it suitable for both formal events and casual wear. This watch is an investment that combines style, functionality, and heritage. Its rich history, impeccable craftsmanship, and versatile design make it a must-have for anyone who appreciates quality timepieces.

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Key Features

Automatic movement with 54-hour power reserve
300-meter water resistance for diving
Chronograph function for precise timing
Stainless steel case with polished finish
Rotating bezel for tracking elapsed time
Black dial with Arabic numeral indexes

Specifications

Brand

Longines

Family

HydroConquest

Model

Hydroconquest Chronograph L688

Reference

L3.696.4.53.6

Movement

l688-2

Movement Features

Hours, Minutes, Small Seconds
Date
Chronograph, Column wheel

Case

Stainless Steel 41mm

Dial Color

Black

Water Resistance

300

Current Listings

Longines Hydroconquest Blue 39mm - $1150

Longines - Hydroconquest · $1,150

A blue dial Longines Hydroconquest 39mm watch with a full kit, in excellent condition and keeping good time.

Condition: Great condition
Year purchased: 2025
Warranty duration: 5 years

Posted at

Mar 1, 2026, 8:14 PM

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Longines Hydroconquest 41mm Two Tone

Longines - Hydroconquest 41mm Two Tone · $999

A Longines Hydroconquest 41mm Two Tone watch with a black dial and two tone finish. It is in very good condition with some minor wear.

Condition: Very Good Pre Owned Condition
Diameter: 41mm

Posted at

Feb 27, 2026, 3:34 PM

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View listing on r/WatchExchange

Longines HydroConquest GMT 41mm L3.790.4

Longines - L3.790.4 · $1,799

This Longines HydroConquest GMT is a 41mm watch featuring a 6.5 inch bracelet and an aftermarket rubber strap with deployant.

Bracelet Length: 6.5 inches
Case Size: 41mm

Posted at

Feb 19, 2026, 5:35 PM

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View listing on r/WatchExchange

Longines HydroConquest 43mm Automatic – Black Dial – Full Kit – $1,095

Longines - L3.782.4 · $1,095

This Longines HydroConquest automatic watch features a black dial and 43mm case size, which provides a strong wrist presence.

Condition: very good
Case size: 43mm diameter
Case wear: normal wear consistent with careful use

Posted at

Feb 18, 2026, 4:40 PM

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Longines Hydroconquest 41m Green full kit with OEM bracelet and rubber strap

Longines - Hydroconquest 41m · $975

A green ceramic automatic watch from Longines, part of the Hydroconquest series, featuring a Swiss movement with 72-hour power reserve.

Condition: Used with signs of wear
Case diameter: 41 mm
Water resistance: 300m / 30 bar
Movement: Longines Calibre L888 series with 72hr power reserve

Posted at

Feb 16, 2026, 4:12 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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View listing on RolexForums