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Longines HydroConquest 41mm Mens Watch
Ref. L37813967
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Stepping up in the same colour and case shape
The HydroConquest has been Longines' working diver since its 2007 launch, and this generation marks a meaningful upgrade over its predecessor: the bezel insert is now ceramic rather than anodised aluminium, which means it will still look unmarked years from now rather than showing every knock from a tank valve or a boat rail. At 41mm with a lug-to-lug of just over 51mm, this sits on the larger side, yet the 11.9mm case height keeps it from riding proud of the wrist — and that flatness is worth noting on a watch rated to 300 metres, where the case engineering required to reach that depth usually adds bulk. It goes under a cuff without forcing a decision about which watch to leave at home. The two-tone execution — bare steel against yellow PVD — is unapologetic about its look; the sunray blue dial and gilt hands lean into it rather than softening it. The L888 runs at 25,200 vph, a deliberate choice to stretch its power reserve to 72 hours, and the diving extension built into the folding clasp means it can go straight from a wetsuit to a cuff without tools. Manual pin-and-collar sizing on the clasp handles the finer fit from there.
- Reference
- L37813967
- Brand
- Longines
- Collection
- HydroConquest
- Case size
- 41mm
- Case thickness
- 11.9mm
- Lug width
- 21mm
- Case material
- Two-tone
- Case shape
- Round
- Dial
- Blue
- Crystal
- Sapphire
- Bezel
- Rotating
- Movement
- Automatic
- Calibre
- ETA A31.L11
- Functions
- Date
- Water resistance
- 300m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Two-tone
- Clasp
- Folding clasp
- Lume
- Super-LumiNova
- Retailer
- Mappin & Webb
Additional specifications
- Lug-to-lug
- 51.10mm
- Power reserve
- 72 hours
- Origin
- Swiss made
Learn more about Longines
Auguste Agassiz began trading watches in Saint-Imier in 1832, but the modern company dates from 1860, when his nephew Ernest Francillon built a factory in the meadows beside the Suze — the longines of the local dialect — and consolidated the scattered outworkers of the region under one roof.
Longines registered its winged hourglass in 1889. It is the oldest watch trademark still in continuous use.
The company's identity was built on precision and on timing things in public. It supplied chronographs for the first modern Olympic events it timed in 1896, timed the 1912 Federal Gymnastics Festival with a broken-wire mechanism accurate to a hundredth of a second, and developed the photo-finish camera and the quartz timing devices used across twentieth-century athletics.
Its aviation associations are equally deep. Longines instruments were carried by Charles Lindbergh across the Atlantic in 1927, and the Hour Angle watch, designed to Lindbergh's own specification to simplify longitude calculation, remains in the catalogue. Amelia Earhart and Howard Hughes both navigated by Longines.
The house was among the most decorated at nineteenth-century observatory trials, holding numerous precision records. Since joining the Swatch Group in 1983 it has occupied the accessible-heritage position: exclusive ETA-based movements, archive-driven designs through the Heritage line, and volume that makes it one of the group's most important brands.
- 1860
- Ernest Francillon builds the factory at Les Longines.
- 1889
- The winged hourglass is registered — the oldest watch trademark in use.
- 1912
- Broken-wire timing achieves hundredth-second accuracy.
- 1927
- Lindbergh crosses the Atlantic with Longines instruments.
- 1983
- Becomes part of the Swatch Group.
Also in 7 collections
This watch appears in the Longines HydroConquest range (42), Back in Stock (3,734), Automatic Watches (1,570), Blue Dial Watches (714), Sports Watches (707), Dive Watches (505) and Two-Tone Watches (386).
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 300m water resistance, rated for actual diving
- Sapphire crystal, which resists scratching
- 72-hour reserve survives a weekend off the wrist
- Luminous hands and markers for low light
- Sits in the lower half of Longines's range as we list it
Longines HydroConquest alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | L37813967 | YA136360 | SPB519J1 |
|---|---|---|---|
| Price | £1,900 | £1,890 | £1,700 |
| Case size | 41mm | 40mm | 42mm |
| Water resistance | 300m | 300m | 300m |
| Movement | Automatic | Automatic | Automatic |
| Strap | Stainless steel bracelet | Ceramic bracelet | Stainless steel bracelet |
| Power reserve | 72 hours | 56 hours | 72 hours |
| This watch | Closely matched | Closely matched |
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 300m it is rated for swimming, snorkelling and recreational diving.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedHow long does it run for when it's not worn?
About 72 hours fully wound — enough to sit off the wrist over a weekend and still be running.
What size strap does it take?
21mm. Any strap of that width will fit, and on most modern watches quick-release bars make the swap a two-minute job with no tools.
Will it fit my wrist?
Lug-to-lug is 51.10mm, which suits wrists from roughly 17.5cm (7 inches) upward.
Lug-to-lug decides fit more than case diameter does.
How to size a watch to your wristIs it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Mappin & Webb is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
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