Longines HydroConquest GMT

The HydroConquest Collection has become a popular staple in the Longines lineup since its launch in 2007. For more than fifteen years it has slowly evolved to include more than two-dozen iterations—some of which are among the brand’s top sellers. Today, for the first time, Longines is expanding the collection with a GMT line in a newly designed case and featuring a Longines’ exclusive movement.  

Longines HydroConquest GMT Watch Review
Longines HydroConquest GMT @calibre321


Longines HydroConquest GMT Watch Review
The HydroConquest GMT retains its 120-click unidirectional, ceramic dive bezel @calibre321

Longines released its first dual-time wristwatch way back in 1925. The brand would pay homage to this timepiece with last year’s release of the hugely popular Spirit Zulu Time GMT and the subsequent Zulu Time 39mm. But while those watches are rooted firmly in the watchmaker’s heritage of ‘avigation,’ the new Hydroconquest GMT draws inspiration from the world of water sport.

Longines HydroConquest GMT Watch Review
Brown and green colourways have gilt highlights @calibre321

Unlike the Zulu Time, the HydroConquest GMT allows travellers to track two time zones without sacrificing all the functionality of a dive watch’s elapsed time bezel–placing it in a sportier category like Seiko’s 1968 Diver’s GMT, the Bremont S302, or Omega’s Diver 300m GMT Chronograph.

Longines HydroConquest GMT Watch Review
Redesigned H-link bracelet with female endlinks  @calibre321

For this latest evolution of the HydroConquest, Longines has fashioned a more retro-inspired silhouette with all the latest technological bells and whistles. The 41mm stainless steel case is less angular than its predecessors and full of gentle, curvaceous lines, alternating between polished and satin-finished planes to achieve a more sophisticated aesthetic. It features a redesigned screw-down crown and case back, less pronounced crown guards, and fresh gear-work knurling on the unidirectional bezel. Even with the GMT movement on the inside, case thickness remains a restrained 12.9mm (versus 11.9mm on the three-hand model, or 13.9mm on the Zulu Time).

Longines HydroConquest GMT Watch Review
Stealthy two-tone 24-hour track in the chapter ring @calibre321

The HydroConquest GMT maintains its ceramic dive bezel insert and familiar font; however, it is equipped with a more pronounced luminescent pip at the 60-minute marker.

Longines HydroConquest GMT Watch Review
More traditional diver dial layout @calibre321

The watch is available in four colourways with green, brown, black, and blue sunray dials with flat sapphire glass. Stealthily placed in the outer chapter ring is a two-tone 24-hour scale, but gone are the cardinal Arabic numerals that have characterized both the Conquest and HydroConquest models for years. In their place are more traditional dive markers, including applied circular plots and baton-style indicators, as well as the tell-tale inverted triangle at twelve. This is not unlike the layout we find on the Submariner 116610, only the circles and batons have been interchanged. The handset, however, will look familiar, with a lollipop seconds and the addition of an arrow-tipped GMT hand. The brown and green references feature gilt highlights, while the black and blue models showcase silvered polish. All dial elements, including the bezel pip, are treated with Super-LumiNova. There is a framed date window at three.

Longines HydroConquest GMT Watch Review
Equipped with on-the-fly micro-adjust for the first time @calibre321

Water-resistant to a dive-ready 300 metres, the HydroConquest GMT comes on a redesigned, stainless steel H-link bracelet (with female endlinks) that is equipped with…wait for it…an on-the-fly micro-adjusting clasp! The mechanism can also be used to expand the bracelet sizing to fit over a wetsuit cuff. This is the bracelet (or clasp), in some respect, that I have been waiting for. This is a first for Longines, and I hope that the brand will make it available for the Spirit line in the future.

Longines HydroConquest GMT Watch Review
Redesigned case shape with gentler curves @calibre321

In addition to the bracelet—and to match certain dial colours—the watch will also be available on a blue or black fitted rubber strap. These will feature the brand’s micro-adjusting deployant clasp. A khaki-coloured NATO is also an option.

Longines HydroConquest GMT Watch Review
New screw down caseback @calibre321

Powering the watch is the Longines’ exclusive Calibre L844.5–the same movement we find in the Zulu Time, minus the COSC certification. The calibre is based on the ETA A31.L01 and features a silicon balance-spring—in addition to other innovative anti-magnetic components—making it ten times more resistant to magnetic fields than the ISO 764 standard. It has a beat rate of 3.5Hz and a power reserve of 72 hours. This is backed by Longines 5-year warranty.

Longines HydroConquest GMT Watch Review
Swiss Super-LumiNova @calibre321


Case316L Stainless Steel
41mm Diameter
12.9mm Thick
21mm Lug Width
Screw Down Crown & Case Back
120-Click Unidirectional Ceramic Bezel
300m Water Resistance
Dial & CrystalSapphire Crystal /w AR
Sunray Dial
Applied Markers
Snowflake Handset
Date Window @ 3
21 Jewels
25 200bph
72-Hour Power Reserve
StrapStainless Steel H-Link Bracelet
/w On-The-Fly Micro-adjust
Fitted Rubber /w Deployant Clasp
Fabric NATO

Longines HydroConquest GMT


Longines HydroConquest GMT Watch Review
Jumping-hour Calibre L844.5 @calibre321

Of Interest

The Longines HydroConquest GMT really feels like a maturing of the HydroConquest collection. The more sinuous case design, paired with sunray dials and matching ceramic bezels, cuts a more elegant a figure, while the dive bezel and impressive water resistance keep close to its sporty roots. I feel some influence here from the Spirit Collection in colour choice and tone on tone colour-matching–which is a good thing. The more traditional dial layout is also a welcome progression. And I really like the attention to detail that provides each watch in the GMT lineup its own personality–such as the arrow-tipped GMT hand matching the GMT dial decal in the black reference.

Longines HydroConquest GMT Watch Review
Sporty sophistication @calibre321


While I am really pleased to see an on-the-fly micro-adjusting clasp on a nicely finished bracelet with female endlinks, the cherry on the top would have been screwed links, rather than push pin. A 21mm lug width also limits aftermarket strap options.

Longines HydroConquest GMT Watch Review
Fitted rubber strap option with deployant clasp @calibre321

Final Thoughts

The Longines HydroConquest GMT is a thoughtful unfolding of the HydroConquest Collection. Rather than being simply a repeat of the Spirit Zulu Time, I like that the brand has kept this watch a diver first and a GMT second. This way, it has a character all its own–not to mention a function and a purpose to itself. Despite its elegant trappings, the HydroConquest GMT feels like a gentleman’s sports watch and a fantastic option for those who like to be adventure-ready when they travel. With its impressive water resistance, dive bezel, micro-adjusting clasp, and robust “jumping-hour” movement, the HydroConquest looks like an attractive, well-considered option as your go-to travel watch. I have often wondered why I have not yet purchased the Zulu Time for myself, but perhaps I was unwittingly waiting for this.

The HydroConquest GMT retails for $2775USD ($3600CAD) on the bracelet. For more information, please visit the brand website.

Longines HydroConquest GMT Watch Review
Longines HydroConquest GMT @calibre321

About the author

Brent Robillard is a writer, educator, craftsman, and watch enthusiast. He is the author of four novels. You can follow him on Instagram.

Off The Cuff articles are full-length, hands-on reviews of the watch in question and represent the opinion of the author only. All photos are original, unless specified otherwise. If you would like to have your watch reviewed on this site, contact us here.

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5 thoughts on “Longines HydroConquest GMT

  1. Very friggin cool. I love Longines, no secret there, and this just checks all the right boxes for me. Great article brotha, always a great read from you.

  2. Well so much for my post question 🤣… Well it’s definitely a better fit for me with adjustable bracelet and dive capable features… They took the time to do all these nice antimagnetic features and dive rated and put in a COSC rated movement but then decided not to certify❓ That’s just crazy‼️ With the certification you could have marketed at $1000 US higher then what listed… Any insight on why they made that decision❓ Great read as always Robi🙌🏽😎 Love ya brother👍🏽

    1. My guess is that with climbing prices, the idea here is to keep the price accessible. The benefit is to the consumer, in the end. Cheers, my friend👊

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