Casio
Casio Oceanus 40 mm Green Quartz
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.
Casio · Oceanus
Casio Oceanus 40 mm Green Quartz
Reference 28851OR.63
Reference at a glance
- Brand
- Casio
- Collection
- Oceanus
- Model
- Casio Oceanus 40 mm Green Quartz
- Reference number
- 28851OR.63
- Year / era
- 1957 · 1950s — pre-quartz mechanical era
- Complication
- Moon phase
- Movement
- Automatic, 24 jewels
- Case material
- Quartz TPT
- Dial type
- Green sunburst
- Strap / bracelet
- Rubber strap with titanium clasp
- Water resistance
- 30 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 40 mm
- Case thickness
- 14.1 mm
- Case material
- Quartz TPT
- Bezel
- Baguette diamond rainbow
- Crystal
- Anti-reflective sapphire, double-domed
- Dial
- Green sunburst
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Applied Roman numerals
- Bracelet / strap
- Rubber strap with titanium clasp
- Clasp / buckle
- Pin buckle in matching case metal
- Water resistance
- 30 m
Movement
- Movement / calibre
- Calibre 70E — Automatic, 24 jewels
- Movement type
- Automatic with micro-rotor
- Frequency
- 28,800 vph (4 Hz)
- Power reserve
- 70 hours
- Number of jewels
- 33 jewels
- Complications
- Moon phase
- Functions
- Hours, minutes, small seconds
- Watchmaker
- Finishing, assembly and timing are carried out in the manufacture's own atelier.
Production & market
- Production period
- 1957 – 1968
- Limited-edition quantity
- Not applicable
- Current market information
- Values have stabilised after the 2022 correction; condition and box-and-papers drive the premium.
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
Casio Oceanus 40 mm Green Quartz sits within Casio's Oceanus line, introduced in 1957. It carries the house codes established since 1946 — quartz tpt case, green sunburst dial and automatic, 24 jewels — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
- The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
- The movement's bridges are decorated even where they will never be seen once the watch is cased.
The House
Casio
Brand facts
- Founding year
- 1946
- Founder
- Tadao Kashio
- Headquarters
- Japan
- Tier
- Japanese
- Major collections
- G-Shock, Edifice, Oceanus, Pro Trek, Vintage
- Signature technologies
- In-house hairspring production · Shock-absorbing movement mounting
- Famous movements
- Spring Drive · Eco-Drive solar quartz · Automatic, 24 jewels · High-accuracy quartz
- Notable watches
- Casio G-Shock 39 mm Blue 18k (1998) · Casio G-Shock 42 mm Black Ceramic (2002) · Casio G-Shock 43 mm Salmon 18k (1985) · Casio G-Shock 42 mm Silvered Sapphire (2004)
Brand history
Casio has spent more than 80 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's G-Shock, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Tadao Kashio established Casio in 1946, working from Japan at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Casio calibre produced today.
Historical milestones
1946
Tadao Kashio founds Casio in Japan.
1969
The quartz era forces Casio to redefine mechanical watchmaking.
1990
Casio enters the modern collector market with its signature lines.
2024
Casio continues to produce G-Shock, Edifice, Oceanus and other icons in limited numbers.