Roger Dubuis debuts its Rarities programme, a vehicle for one-offs and client-led projects with the Moonlight Excalibur, a watch that feels like a technical and visual exercise pushed to its limits.
The RD115 calibre (is the star of the horological show) sits literally at the centre of it. The tourbillon is placed in the middle of the dial, forcing everything else to work around it. Traditional hands are abandoned in favour of rotating discs for the hours and minutes, which circle the movement rather than point across it. It is not the easiest way to display time, but it is coherent. The mechanics behind it are ingeniously thought through, with a reworked gear train and a separate system to disengage the discs when setting the watch.
At the heart of the Roger Dubuis Excalibur Moonlight, a hand-engraved lunar tourbillon anchors a celestial
stage of rotating Murano-glass discs that orbit the dial to track time through luminescent constellations.
All of the above could have resulted in a lot of visual noise, but Roger Dubuis has handled it with intelligence and panache. The dial is built in clearly defined layers. A blue flange upholds the applied indexes – filled with black Super-LumiNova – while two translucent discs carry the indications. Over that sits the tourbillon cage, topped with a small, engraved moon that rotates once per minute. Around it, constellations are mapped in fine detail, visible without overwhelming the rest of the watch.
Turn it over to discover a movement more familiar with the brand’s style: openworked, sharply drawn bridges and finishing that justifies the Geneva Seal. The sapphire back is laser-engraved with a constellation of alveoli inspired by the stars of the Milky Way. These engravings are hand-filled with a green luminescent material that glows in the dark, simulating a starry night sky. The visible barrel cover can be customised with constellations corresponding to a date chosen by the owner.
The caseback of the Roger Dubuis Excalibur Moonlight transforms the sapphire crystal into a glowing
map of the galaxy. Across the 283 movement components, one can observe 19 distinct hand-finishing
techniques, including perlage on the main plate and circular Côtes de Genève on the bridges.
At 45mm, the watch is substantial, but the design strategy helps manage its size. The black DLC titanium absorbs light, making the watch appear slightly smaller and more compact on the wrist, while the “Cosmic Blue” and CVD blue brass elements prevent the dark palette from looking flat.
The Excalibur Moonlight successfully shrinks the vastness of the cosmos into a “Hyper Horology” instrument on the wrist, balancing its scale with weightless materials and intricate, luminescent artistry.
Author: Andrew Hildreth
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