The Omega Caliber 1863 is a manual-winding chronograph movement derived directly from the Caliber 1861—both of which trace their lineage back to the iconic Caliber 861, itself rooted in the robust Lemania 1873 base. Introduced in the 1990s, the 1863 was developed specifically for display caseback versions of the Omega Speedmaster Professional, offering the same robust mechanics as the 1861 but with a luxuriously decorated finish.
Where the 1861 was engineered with tool-watch pragmatism in mind, the 1863 was made to be seen, admired, and appreciated—a mechanical showcase of the Moonwatch’s inner workings.
Type: Manual-winding chronograph
Functions: Hours, minutes, small seconds at 9 o'clock, chronograph (central seconds, 30-minute and 12-hour counters)
Base: Lemania 1873
Jewels: 18
Frequency: 21,600 vibrations per hour (3 Hz)
Power Reserve: ~48 hours
Finish: Geneva stripes (Côtes de Genève), polished levers, beveled edges, and rhodium plating
Chronograph Mechanism: Cam-actuated, horizontal clutch
Hacking Seconds: No
Display Caseback: Yes – exclusive to sapphire crystal Speedmasters
Mechanically, the 1863 is identical to the 1861 in terms of performance and reliability. However, it receives additional hand-finishing and visual enhancements, making it more appealing to collectors and enthusiasts who value movement aesthetics.
The Caliber 1863 is found in Speedmaster Professional Moonwatch models with a sapphire crystal caseback, such as:
Reference 3573.50.00 – Often referred to as the “Sapphire Sandwich” (sapphire front and back)
Limited Editions – Including Apollo mission tributes, special anniversary pieces, and box-set collectibles
Museum and numbered series – Occasionally featuring skeletonized or engraved 1863 movements
These watches are nearly identical to their Hesalite-cased 1861 counterparts but are aimed at customers who want to visually appreciate the legendary chronograph movement beating inside.
Just like the 1861, the Caliber 1863:
Uses a cam-switching chronograph system for reliability
Is manual-winding, encouraging interaction and connection with the watch
Offers space-tested durability, as its architecture is essentially unchanged from NASA-certified movements
Delivers classic mechanical charm with modern reliability
It does not feature hacking seconds or a Co-Axial escapement, which keeps it authentic to its Moon-era lineage.
The 1863 is known for being:
Serviceable by most experienced watchmakers
Backed by Omega’s robust parts and support network
Mechanically stable, with decades of proven field performance
Its components are shared with the 1861, making long-term maintenance straightforward.
The Caliber 1863 is beloved by:
Collectors who want a Moonwatch with a view
Enthusiasts of manual chronographs
Watch lovers who value traditional finishing techniques
Those who want the mechanical experience of winding and watching time tick
The “Sapphire Sandwich” Speedmasters have earned a strong following because they combine tool-watch functionality with luxury aesthetics, and the 1863 movement is at the center of that appeal.
The Omega Caliber 1863 takes the rugged history of the Moonwatch and dresses it in a way that lets you see the movement of history—literally. It remains one of the most respected manual chronograph movements in the world, offering both NASA-proven performance and visual beauty.
If you want a Speedmaster that celebrates its mechanical roots and lets you admire them through a sapphire caseback, the 1863 is the perfect choice—a chronograph engine built for space, elevated for collectors.
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