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.
IWC Schaffhausen · Aquatimer
IWC Schaffhausen Aquatimer 37 mm Slate 18k
Reference 81989OR.99
Reference at a glance
- Brand
- IWC Schaffhausen
- Collection
- Aquatimer
- Model
- IWC Schaffhausen Aquatimer 37 mm Slate 18k
- Reference number
- 81989OR.99
- Year / era
- 1996 · 1990s — mechanical revival
- Complication
- Minute repeater
- Movement
- In-house automatic, chronometer certified
- Case material
- 18k yellow gold
- Dial type
- Slate grey
- Strap / bracelet
- Alligator leather with folding clasp
- Water resistance
- 500 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 37 mm
- Case thickness
- 8.8 mm
- Case material
- 18k yellow gold
- Bezel
- Fixed brushed titanium
- Crystal
- Anti-reflective sapphire, double-domed
- Dial
- Slate grey
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Diamond-set hour markers
- Bracelet / strap
- Alligator leather with folding clasp
- Clasp / buckle
- Folding clasp in matching case metal
- Water resistance
- 500 m
Movement
- Movement / calibre
- Calibre 73E — In-house automatic, chronometer certified
- Movement type
- Automatic, self-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 72 hours
- Number of jewels
- 33 jewels
- Complications
- Minute repeater
- Functions
- Flying tourbillon, power reserve
- Watchmaker
- The calibre is built in-house and adjusted in five positions before delivery.
Production & market
- Production period
- 1996 – 2007
- Limited-edition quantity
- Not applicable
- Current market information
- Values have stabilised after the 2022 correction; condition and box-and-papers drive the premium.
Designer
In-house design studio
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
IWC Schaffhausen Aquatimer 37 mm Slate 18k sits within IWC Schaffhausen's Aquatimer line, introduced in 1996. It carries the house codes established since 1868 — 18k yellow gold case, slate grey dial and in-house automatic, chronometer certified — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
- Early production dials show a slightly different minute track, and collectors pay a premium for them.
- The movement's bridges are decorated even where they will never be seen once the watch is cased.
The House
IWC Schaffhausen
Brand facts
- Founding year
- 1868
- Founder
- Florentine Ariosto Jones
- Headquarters
- Switzerland
- Tier
- Luxury
- Major collections
- Portugieser, Pilot's Watch, Portofino, Ingenieur, Aquatimer, Da Vinci
- Signature technologies
- Proprietary case-hardening and polishing · Shock-absorbing movement mounting · Certified chronometer regulation
- Famous movements
- In-house manual-winding · In-house automatic, Superlative Chronometer · In-house automatic chronograph · In-house automatic, chronometer certified
- Notable watches
- IWC Schaffhausen Portugieser 38 mm Blue 18k (2000) · IWC Schaffhausen Portugieser 40 mm Black Carbon (1962) · IWC Schaffhausen Portugieser 38 mm Silvered 18k (1987) · IWC Schaffhausen Portugieser 36 mm Slate Grade (1991)
Brand history
IWC Schaffhausen has spent more than 158 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Portugieser, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Florentine Ariosto Jones established IWC Schaffhausen in 1868, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every IWC Schaffhausen calibre produced today.
Historical milestones
1868
Florentine Ariosto Jones founds IWC Schaffhausen in Switzerland.
1899
IWC Schaffhausen earns its first international recognition for precision timekeeping.
1969
The quartz era forces IWC Schaffhausen to redefine mechanical watchmaking.
1990
IWC Schaffhausen enters the modern collector market with its signature lines.
2024
IWC Schaffhausen continues to produce Portugieser, Pilot's Watch, Portofino and other icons in limited numbers.