Short answer
A replica Rendez-Vous Back of the Moon is a copy of a Swiss women's dress watch that carries a moon-phase display at six o'clock and an engraved moon motif on the caseback. Copies sell from about $60 to $600. The ones worth owning sit in the $250 to $600 band: a rotating 59-tooth moon disc, sapphire glass, a mother-of-pearl or guilloche dial, and a decorated automatic movement. Budget copies glue a flat printed moon to the dial and use mineral glass.
What the original is built to show
- A moon-phase aperture at 6 o'clock with a dark blue disc, polished moon, and stars.
- A dial in mother-of-pearl or stamped guilloche, with applied numerals or set stones.
- A caseback engraved with the far side of the moon, which gives the model its name.
- A small case, 33 mm to 36 mm, thin profile, alligator or calf strap.
Before you shop
- Fix the reference and case size you want, so sellers cannot swap specs on you.
- Set a budget band and refuse to move above it.
- Decide between quartz and automatic, since the moon disc differs on each.
- Measure your wrist and confirm the strap length suits it.
How to inspect one, step by step
- Ask for the reference number and match the case diameter and thickness against the original spec sheet.
- Request close photos of the dial under raking light to confirm the moon is a rotating disc and not a print.
- Examine the edge of the moon aperture for burrs, paint bleed, or a visible sticker line.
- Check the applied markers and stones: each one should sit level with no glue haze around it.
- Study the caseback engraving under magnification, looking for shallow lasering and soft edges.
- Ask which movement sits inside and whether it is automatic or quartz, then verify the answer against the second-hand sweep.
- Work the crown through winding, hand-setting, and moon correction to test the keyless works.
- Flex the strap and inspect stitching, leather grain, and the tang or deployant fit.
- Confirm the water resistance claim and ask whether the case was pressure-tested.
- Pay through a method with buyer protection, then inspect the watch on arrival inside the return window.
Red flags
- Stock catalog images only, with no photo of the actual unit.
- A price under $100 paired with claims of sapphire glass and an automatic movement.
- A moon that does not advance when you set it, or that jumps back to the same spot.
- A seller who cannot name the movement or the factory tier.
- No stated return policy, or a return window shorter than the shipping time.
After the purchase
Set the moon disc against a known moon phase, then expect to correct it about once every two and a half years, since a 59-tooth disc drifts by one day in that span. Treat any water resistance rating on a replica as a claim rather than a promise and keep the watch out of pools and showers. An automatic copy needs a service every three to five years, and the moon mechanism is the part that wears first. Store it on a winder or wind it twice a week to keep the date and moon wheels aligned.