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Longines HydroConquest 42 mm Slate Quartz
Longines HydroConquest 42 mm Slate Quartz — Front view

Front view

Dial, hands and bezel as delivered.

Longines HydroConquest 42 mm Slate Quartz — Case-back view

Case-back view

Case-back engraving and, where fitted, the sapphire display.

Movement

Movement

Calibre with its finishing and decoration.

On the wrist

On the wrist

Worn shot for proportion and strap drape.

Longines · HydroConquest

Longines HydroConquest 42 mm Slate Quartz

Reference 35458OR.71

Reference at a glance

Brand
Longines
Collection
HydroConquest
Model
Longines HydroConquest 42 mm Slate Quartz
Reference number
35458OR.71
Year / era
2023 · 2020s — modern production
Complication
Flyback chronograph
Movement
High-beat automatic
Case material
Quartz TPT
Dial type
Slate grey
Strap / bracelet
Rubber strap with titanium clasp
Water resistance
100 m
Limited-edition status
Regular production, not a limited edition
Compare this reference

Case, dial & bracelet

Case dimensions
42 mm
Case thickness
8.8 mm
Case material
Quartz TPT
Bezel
Unidirectional ceramic 60-minute
Crystal
Box sapphire with AR coating
Dial
Slate grey
Hands
Faceted dauphine hands, polished by hand
Indexes
Applied faceted white-gold indexes
Bracelet / strap
Rubber strap with titanium clasp
Clasp / buckle
Triple-folding clasp with safety catch
Water resistance
100 m

Movement

Movement / calibre
Calibre 40F — High-beat automatic
Movement type
High-frequency automatic
Frequency
28,800 vph (4 Hz)
Power reserve
70 hours
Number of jewels
21 jewels
Complications
Flyback chronograph
Functions
Perpetual calendar, leap year
Watchmaker
Assembled and regulated by a single watchmaker, who signs off the piece before casing.

Production & market

Production period
2023 – 2029
Limited-edition quantity
Not applicable
Current market information
Trades close to retail on the secondary market, with steady demand for full-set examples.

Designer

Marc Newson

Marc Newson is an Australian industrial designer whose work spans Qantas cabins, Apple hardware and Jaeger-LeCoultre's Atmos clocks; his watch design reduces the object to pure geometry and legibility.

Historical significance

Longines HydroConquest 42 mm Slate Quartz sits within Longines's HydroConquest line, introduced in 2023. It carries the house codes established since 1832 — quartz tpt case, slate grey dial and high-beat automatic — and is one of the references collectors use to date the evolution of the collection.

Interesting facts

  • The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
  • Early production dials show a slightly different minute track, and collectors pay a premium for them.
  • The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
LO

The House

Longines

Brand facts

Founding year
1832
Founder
Auguste Agassiz
Headquarters
Switzerland
Tier
Premium
Major collections
Master Collection, HydroConquest, Spirit, Legend Diver, DolceVita, Conquest
Signature technologies
Proprietary case-hardening and polishing · Shock-absorbing movement mounting · In-house hairspring production
Famous movements
High-beat automatic · Automatic chronograph · Automatic, Swiss lever escapement · Spring Drive
Notable watches
Longines Master Collection 44 mm Green Ceramic (1974) · Longines Master Collection 40 mm Meteorite 18k (1964) · Longines Master Collection 41 mm Black 18k (1998) · Longines Master Collection 44 mm Skeletonised Sapphire (1969)

Brand history

Longines has spent more than 194 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Master Collection, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.

Auguste Agassiz established Longines in 1832, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Longines calibre produced today.

Historical milestones

  1. 1832

    Auguste Agassiz founds Longines in Switzerland.

  2. 1872

    Longines earns its first international recognition for precision timekeeping.

  3. 1969

    The quartz era forces Longines to redefine mechanical watchmaking.

  4. 1990

    Longines enters the modern collector market with its signature lines.

  5. 2024

    Longines continues to produce Master Collection, HydroConquest, Spirit and other icons in limited numbers.

More HydroConquest