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Longines HydroConquest 41mm Mens Watch
Ref. L37813587
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Stepping up in the same colour and case shape
The HydroConquest has been Longines' serious dive proposition since 2007, and this generation represents a deliberate tidying of the line — cleaner dial architecture, a ceramic bezel insert that matches the sunray black finish rather than contrasting with it, and a more considered integration of the two-tone treatment. The rose gold-tone PVD appears selectively, on the crown, the bezel edge, and the inner bracelet links, which prevents it from reading as decoration applied as an afterthought. At 11.9mm thick for a watch rated to 300 metres, the profile is genuinely restrained for the category, and the straight elongated lugs that Longines favours will push the wrist presence beyond what the 41mm diameter alone suggests — it wears with more authority than the number implies. The L888 underneath is an ETA movement reworked within Swatch Group specifically for Longines, its beat rate dropped to 3.5Hz to reach a 72-hour power reserve — meaningful for a watch that will genuinely come off the wrist between weekends. The bracelet clasp carries a wetsuit extension and adjusts through pinholes inside the casing for fine sizing, with full resizing done by removing friction-pin links rather than spring bars — a more stable solution for a bracelet that will spend time in salt water.
- Reference
- L37813587
- Brand
- Longines
- Collection
- HydroConquest
- Case size
- 41mm
- Case thickness
- 11.9mm
- Lug width
- 21mm
- Case material
- Two-tone
- Case shape
- Round
- Dial
- Black
- Crystal
- Sapphire
- Bezel
- Unidirectional rotating
- Movement
- Automatic
- Calibre
- ETA A31.L01
- Functions
- Date
- Water resistance
- 300m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Two-tone
- Clasp
- Folding clasp
- Lume
- Luminous
- Retailer
- Goldsmiths
Additional specifications
- Power reserve
- 72 hours
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 6 collections
This watch appears in the Longines HydroConquest range (42), Back in Stock (3,734), Automatic Watches (1,570), Sports Watches (707), Dive Watches (505) and Two-Tone Watches (386).
Temporarily out of stock
Goldsmiths is not currently taking orders for this reference. Last listed as available on 5 October 2026. Stock is checked nightly and this page updates when it returns.
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 | L37813587 | 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.
Is it a men's or women's watch?
Listed as men's.
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