The full moon Fifty Fathoms replica is a copy of the Blancpain Fifty Fathoms Bathyscaphe Quantième Complet Phases de Lune, a dive watch that adds a full calendar and a moon phase to the classic Fifty Fathoms case. The best 1:1 versions run a clone automatic calendar movement, keep the 43 mm case, and place the day, date, month, and moon readouts in the same spots as the original. The moon phase disc is the one part that separates a serious copy from a cheap print job.
fifty fathoms full moon replica
What the original "full moon" Fifty Fathoms is
Blancpain built this model by dropping a complete calendar into a dive watch, which is a rare mix. The case keeps the dive layout: rotating bezel, strong lume, and a 300 m depth rating on the standard version.
fifty fathoms full moon replica
The dial carries four extra readouts. Day and month sit in windows, the date runs around the rim on a pointer, and a moon phase disc fills the lower part of the dial.
Case size lands near 43 mm, so it wears bigger than a three-hand Bathyscaphe. That matters for a replica, because a shrunken case with the same dial layout looks wrong from across a table.
Replica Fifty Fathoms Full Moon: The Ultimate Guide
Why the moon phase is the hardest part to copy
A moon phase is a 59-tooth disc that turns once every 29.5 days. On a cheap copy, that disc is printed flat, glued in place, and never moves.
On a proper 1:1 build, the disc rides on the calendar train. You see the moon creep forward a little each day, and the disc edge travels past the aperture as the month runs.
How to test the moon phase in 30 seconds
- Pull the crown to the setting position and turn it forward. The moon should step across the window in small jumps, not spin in a full circle.
- Watch the day, date, and month at the same time. A real calendar movement advances each one in sequence, not all at once.
- Check the disc surface. A machined disc sits just below the dial plane with a visible cut edge. A sticker sits flush and shows a hard printed line.
Specs a good replica should match
- Case: about 43 mm wide, 13 to 14 mm thick, brushed sides with polished bevels.
- Water resistance: stamped 300 m on paper. Treat it as splash-proof unless the case back seals well and passes a pressure test.
- Bezel: unidirectional, 120 clicks, ceramic or sapphire insert with lume in the triangle.
- Crystal: domed sapphire with an inner anti-reflective coating.
- Dial: matte or gradient finish, applied markers, and a moon disc with a textured surface.
- Lug width: matches the case so the strap sits tight against the lugs with no gap.
Movement options inside replica Fifty Fathoms moon phase watches
Three movement families turn up in this model, and each one changes both the price and the feel of the calendar.
- Standard Asian automatic with a calendar module: basic day, date, and month. The moon disc often jumps a full cycle instead of stepping each day.
- Clone calendar movement: copies the layout of the original Blancpain calibre. Correct hand stack, slow moon advance, and recessed correctors on the case side.
- Modified ETA or Sellita base: the most stable option. Parts are common, so an independent watchmaker can service it.
Common flaws to catch before you pay
Most returns on this model come down to five things. Check each one in seller photos before ordering, then check again on arrival.
- Moon disc printed on paper instead of a raised disc.
- Month window that reads out of order, such as "MAR" showing after "APR".
- Date pointer that scrapes the dial or floats below the printed track.
- Bezel that sits off-center at 12 o'clock.
- Case back engraving with the wrong depth rating or a serial number repeated across a whole batch.
Case, bezel, and finish checks
Look at the lugs and crown guards first. A sharp, unfinished lug edge is the fastest tell on a replica dive watch.
Bezel action should feel firm with no back play. If the bezel rocks when you press it, the click spring is thin and will fail.
Weight is a rough guide. Hollow bracelets and thin cases feel light in the hand, while solid steel in the 90 to 120 gram range feels closer to the original.
Strap options and what to swap
The Fifty Fathoms line ships on sailcloth, rubber, or a steel bracelet, and replica sellers copy all three. The strap is often the weakest part of the package.
Swap to a rubber or sailcloth strap from a third-party maker if the stock one feels stiff or smells of solvent. It changes the look and costs little.
Price tiers and what each one gets you
- Entry tier: basic movement, printed moon disc, plated finish. Fine as a display piece, weak as a daily wearer.
- Mid tier: clone calendar movement, raised moon disc, sapphire crystal. The best value for regular use.
- Top tier: modified Swiss base movement, hand-finished case, working correctors, and a detailed case back. Closest to the original in feel.
FAQ
Does the moon phase work on a replica full moon Fifty Fathoms?
On mid and top tier copies, yes. The disc advances with the calendar train and completes a cycle every 29.5 days. On entry tier copies the disc is fixed and the moon never moves.
How often do I need to reset the moon phase?
Once a month on most copies, when the date rolls over. If the watch stops for weeks, set the moon against a moon phase calendar so it lines up with the real sky again.
What should I check when the watch arrives?
Test every calendar function before the return window closes. Set day, date, month, and moon, run the watch for 48 hours, and confirm that each one advanced.
Can a jeweler service a replica moon phase watch?
Many will not touch a replica, and some clone calibres have no spare parts. Buy from a seller who offers a service window or a repair option in writing.