Alpina
Alpina Seastrong 36 mm Skeletonised Platinum
Photography on request
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.
Alpina · Seastrong
Alpina Seastrong 36 mm Skeletonised Platinum
Reference 31615OR.55
Reference at a glance
- Brand
- Alpina
- Collection
- Seastrong
- Model
- Alpina Seastrong 36 mm Skeletonised Platinum
- Reference number
- 31615OR.55
- Year / era
- 1994 · 1990s — mechanical revival
- Complication
- Tourbillon
- Movement
- Automatic, 38-hour reserve
- Case material
- Platinum 950
- Dial type
- Skeletonised
- Strap / bracelet
- Oyster bracelet
- Water resistance
- 100 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 36 mm
- Case thickness
- 8.1 mm
- Case material
- Platinum 950
- Bezel
- Bidirectional 24-hour Cerachrom
- Crystal
- Sapphire with internal AR treatment
- Dial
- Skeletonised
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Applied Roman numerals
- Bracelet / strap
- Oyster bracelet
- Clasp / buckle
- Folding clasp in matching case metal
- Water resistance
- 100 m
Movement
- Movement / calibre
- Calibre 11A — Automatic, 38-hour reserve
- Movement type
- Automatic with micro-rotor
- Frequency
- 25,200 vph (3.5 Hz)
- Power reserve
- 10 days
- Number of jewels
- 31 jewels
- Complications
- Tourbillon
- Functions
- GMT second time zone, date
- Watchmaker
- Assembled and regulated by a single watchmaker, who signs off the piece before casing.
Production & market
- Production period
- 1994 – 2003
- Limited-edition quantity
- Not applicable
- Current market information
- Consistently trades above retail; waiting lists at authorised dealers remain long.
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
Alpina Seastrong 36 mm Skeletonised Platinum sits within Alpina's Seastrong line, introduced in 1994. It carries the house codes established since 1883 — platinum 950 case, skeletonised dial and automatic, 38-hour reserve — 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
Alpina
Brand facts
- Founding year
- 1883
- Founder
- Gottlieb Hauser
- Headquarters
- Switzerland
- Tier
- Affordable & Tool Watches
- Major collections
- Alpiner, Seastrong, Startimer, Comtesse
- Signature technologies
- Shock-absorbing movement mounting · Anti-magnetic silicon escapement · In-house hairspring production
- Famous movements
- Quartz · Automatic COSC chronometer · Automatic Powermatic 80 · Automatic, 38-hour reserve
- Notable watches
- Alpina Alpiner 44 mm Silvered Platinum (1955) · Alpina Alpiner 42 mm Black 18k (1966) · Alpina Alpiner 44 mm Ice Carbon (1992) · Alpina Alpiner 44 mm Salmon 18k (1961)
Brand history
Alpina has spent more than 143 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Alpiner, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Gottlieb Hauser established Alpina in 1883, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Alpina calibre produced today.
Historical milestones
1883
Gottlieb Hauser founds Alpina in Switzerland.
1899
Alpina earns its first international recognition for precision timekeeping.
1969
The quartz era forces Alpina to redefine mechanical watchmaking.
1990
Alpina enters the modern collector market with its signature lines.
2024
Alpina continues to produce Alpiner, Seastrong, Startimer and other icons in limited numbers.