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Longines HydroConquest 44mm Stainless Steel
Ref. 406000537490
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Stepping up in the same colour and case shape
The HydroConquest has always been Longines' working diver rather than its dress proposition — built around a 300-metre rating and a rotating bezel, sized to be read at depth rather than admired across a dinner table. At 44mm with a lug-to-lug of 54.7mm it is an unambiguously large watch, and the sunray black dial reads accordingly: generous luminous Arabic numerals at six, nine and twelve, broad hands, and indices that leave nothing uncertain in low light or underwater. The unidirectional bezel is a proper one, not decorative. The L888 is worth knowing. It runs at 25,200 vph rather than the more common 28,800, a deliberate reduction that eases stress on the escapement and extends service intervals, and it carries 72 hours of power reserve — more than most movements at this frequency manage. The bracelet clasp includes a wetsuit extension that adjusts without tools, which on a dive-rated watch of this depth is the kind of detail that earns its keep rather than simply appearing in the specifications.
- Reference
- 406000537490
- Brand
- Longines
- Collection
- HydroConquest
- Case size
- 44mm
- Case thickness
- 11.90mm
- Lug width
- 22mm
- Case material
- Stainless steel
- Case shape
- Round
- Dial
- Black
- Crystal
- Sapphire
- Bezel
- Unidirectional rotating
- Movement
- Automatic
- Calibre
- L888
- Functions
- Date
- Water resistance
- 300m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Silver
- Clasp
- Folding clasp
- Lume
- Super-LumiNova
- Condition
- Pre-owned
- Retailer
- Mappin & Webb
Additional specifications
- Lug-to-lug
- 54.70mm
- 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 7 collections
This watch appears in the Longines HydroConquest range (42), Back in Stock (4,405), Stainless Steel Watches (2,927), Automatic Watches (1,634), Watches 44mm and Over (781), Sports Watches (729) and Dive Watches (521).
Temporarily out of stock
Mappin & Webb is not currently taking orders for this reference. Last listed as available on 16 September 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
Worth knowing
- 44mm sits at the larger end
Price history
This watch is currently at its lowest recorded price. It reached £1,050 on 3 September. Prices are checked every day, and we record any changes.
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?
22mm. 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 54.70mm, which suits wrists from roughly 18.5cm (7¼ 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.
Has the price changed recently?
It's currently at its lowest recorded price since we began tracking it. It's ranged between £735 and £1,050, today it's £735.
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