Front view
Dial, hands and bezel as delivered.
Case-back view
Case-back engraving and, where fitted, the sapphire display.
Movement
Calibre with its finishing and decoration.
On the wrist
Worn shot for proportion and strap drape.
Longines · HydroConquest
Longines HydroConquest 40 mm Salmon 18k
Reference 63931OR.95
Reference at a glance
- Brand
- Longines
- Collection
- HydroConquest
- Model
- Longines HydroConquest 40 mm Salmon 18k
- Reference number
- 63931OR.95
- Year / era
- 1975 · 1970s — quartz-crisis era
- Complication
- Moon phase
- Movement
- Automatic chronograph
- Case material
- 18k rose gold
- Dial type
- Salmon
- Strap / bracelet
- Rubber strap with titanium clasp
- Water resistance
- 500 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 40 mm
- Case thickness
- 10.2 mm
- Case material
- 18k rose gold
- Bezel
- Bidirectional 24-hour Cerachrom
- Crystal
- Box sapphire with AR coating
- Dial
- Salmon
- Hands
- Blued steel Breguet-style hands
- Indexes
- Applied Arabic numerals with luminous coating
- Bracelet / strap
- Rubber strap with titanium clasp
- Clasp / buckle
- Pin buckle in matching case metal
- Water resistance
- 500 m
Movement
- Movement / calibre
- Calibre 9F — Automatic chronograph
- Movement type
- Automatic, self-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 5 days
- Number of jewels
- 40 jewels
- Complications
- Moon phase
- Functions
- Flying tourbillon, power reserve
- Watchmaker
- Assembled and regulated by a single watchmaker, who signs off the piece before casing.
Production & market
- Production period
- 1975 – 1987
- Limited-edition quantity
- Not applicable
- Current market information
- Thin secondary-market supply — pricing is set piece by piece at auction.
Designer
Emmanuel Gueit
Emmanuel Gueit came from a family of Geneva jewellers and was barely into his twenties when he drew the oversized Royal Oak Offshore in 1993 — a watch the house's traditionalists resisted and collectors turned into an icon.
Historical significance
Longines HydroConquest 40 mm Salmon 18k sits within Longines's HydroConquest line, introduced in 1975. It carries the house codes established since 1832 — 18k rose gold case, salmon dial and automatic chronograph — 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 bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
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
1832
Auguste Agassiz founds Longines in Switzerland.
1872
Longines earns its first international recognition for precision timekeeping.
1969
The quartz era forces Longines to redefine mechanical watchmaking.
1990
Longines enters the modern collector market with its signature lines.
2024
Longines continues to produce Master Collection, HydroConquest, Spirit and other icons in limited numbers.
More HydroConquest
Longines HydroConquest 39 mm Skeletonised Ceramic
Ref. 68469OR.64
Longines HydroConquest 44 mm Mother-of-pearl Ceramic
Ref. 12598OR.37
Longines HydroConquest 36 mm Salmon Stainless
Ref. 29984ST.44
Longines HydroConquest 44 mm Ice Quartz
Ref. 47424OR.99
Longines HydroConquest 42 mm Slate Quartz
Ref. 35458OR.71