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.
Blancpain · Fifty Fathoms
Blancpain Fifty Fathoms 36 mm Slate Sapphire
Reference 39011OR.23
Reference at a glance
- Brand
- Blancpain
- Collection
- Fifty Fathoms
- Model
- Blancpain Fifty Fathoms 36 mm Slate Sapphire
- Reference number
- 39011OR.23
- Year / era
- 1978 · 1970s — quartz-crisis era
- Complication
- Minute repeater
- Movement
- In-house manual-winding
- Case material
- Sapphire crystal case
- Dial type
- Slate grey
- Strap / bracelet
- Integrated steel bracelet
- Water resistance
- 50 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 36 mm
- Case thickness
- 14.1 mm
- Case material
- Sapphire crystal case
- Bezel
- Octagonal with 8 hexagonal screws
- Crystal
- Anti-reflective sapphire, double-domed
- Dial
- Slate grey
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Diamond-set hour markers
- Bracelet / strap
- Integrated steel bracelet
- Clasp / buckle
- Titanium deployant clasp
- Water resistance
- 50 m
Movement
- Movement / calibre
- Calibre 48D — In-house manual-winding
- Movement type
- High-frequency automatic
- Frequency
- 28,800 vph (4 Hz)
- Power reserve
- 70 hours
- Number of jewels
- 33 jewels
- Complications
- Minute repeater
- Functions
- Dive time, running seconds
- Watchmaker
- The calibre is built in-house and adjusted in five positions before delivery.
Production & market
- Production period
- 1978 – 1986
- Limited-edition quantity
- Not applicable
- Current market information
- Values have stabilised after the 2022 correction; condition and box-and-papers drive the premium.
Designer
Jean-Jacques Fiechter
The reference was drawn by the manufacture's internal design office, where case, dial and movement architects work alongside the watchmakers rather than as an outside commission.
Historical significance
Blancpain Fifty Fathoms 36 mm Slate Sapphire sits within Blancpain's Fifty Fathoms line, introduced in 1978. It carries the house codes established since 1735 — sapphire crystal case case, slate grey dial and in-house manual-winding — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- Early production dials show a slightly different minute track, and collectors pay a premium for them.
- The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
The House
Blancpain
Brand facts
- Founding year
- 1735
- Founder
- Jehan-Jacques Blancpain
- Headquarters
- Switzerland
- Tier
- Luxury
- Major collections
- Fifty Fathoms, Villeret, Air Command, Bathyscaphe, Le Brassus, Ladybird
- Signature technologies
- Proprietary case-hardening and polishing · Certified chronometer regulation · Shock-absorbing movement mounting
- Famous movements
- In-house automatic, Superlative Chronometer · In-house manual-winding · In-house automatic, chronometer certified · In-house automatic chronograph
- Notable watches
- Blancpain Fifty Fathoms 36 mm Slate Sapphire (1978) · Blancpain Fifty Fathoms 44 mm Mother-of-pearl 18k (1954) · Blancpain Fifty Fathoms 41 mm Skeletonised Quartz (2001) · Blancpain Fifty Fathoms 41 mm Black Stainless (1959)
Brand history
Blancpain has spent more than 291 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Fifty Fathoms, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Jehan-Jacques Blancpain established Blancpain in 1735, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Blancpain calibre produced today.
Historical milestones
1735
Jehan-Jacques Blancpain founds Blancpain in Switzerland.
1775
Blancpain earns its first international recognition for precision timekeeping.
1969
The quartz era forces Blancpain to redefine mechanical watchmaking.
1990
Blancpain enters the modern collector market with its signature lines.
2024
Blancpain continues to produce Fifty Fathoms, Villeret, Air Command and other icons in limited numbers.
More Fifty Fathoms
Blancpain Fifty Fathoms 36 mm Mother-of-pearl Quartz
Ref. 92158OR.59
Blancpain Fifty Fathoms 44 mm Mother-of-pearl 18k
Ref. 98908OR.31
Blancpain Fifty Fathoms 41 mm Skeletonised Quartz
Ref. 36909OR.26
Blancpain Fifty Fathoms 41 mm Black Stainless
Ref. 62568ST.10
Blancpain Fifty Fathoms 41 mm Mother-of-pearl 18k
Ref. 74677OR.47