Answer first: the "Fake Fifty Fathoms 5000" is a replica of the Blancpain Bathyscaphe ref. 5000, a 43mm dive watch rated to 300m and powered by the calibre 1315 with a 120-hour power reserve. No replica on the market matches that movement spec. So the useful way to judge one is to forget the badge, ignore the seller's adjectives, and check what you can see, feel, and measure yourself: case finishing, bezel action, dial printing, date alignment, and how long it actually runs off the wrist.
What the real ref. 5000 is
The Bathyscaphe 5000 is the smaller, cleaner sibling of the classic Fifty Fathoms Automatique. Key specs worth memorizing before you shop:
- 43mm case in steel or black ceramic, roughly 13.4mm thick
- 300m water resistance, unidirectional bezel with a ceramic insert
- Sunburst grey or black dial, date window at 4:30
- Syringe hands, 23mm lug width
- Calibre 1315: three mainspring barrels, silicon balance spring, about 227 parts
That 120-hour reserve is the single most important number, because it is the hardest thing to fake.
The three replica tiers
Budget tier: quartz or a basic 21-jewel automatic, printed dial text, hollow end links, bezel that rattles. Mid tier: Miyota 9015 or an A2824 inside, decent case polish, wrong date wheel font, sapphire crystal with weak anti-reflective coating. High tier: decorated automatic movement, sharper brushing, correct-ish dial finish, lume that works. Even the best tier usually stops between 38 and 45 hours.
The tells that matter
- Power reserve test. Wind it fully, set it down, and check it at 48 hours. The real 1315 keeps going well past 100. Almost every replica is dead.
- Date at 4:30. Check that the window sits square to the dial and the font matches the thickness of the printed text.
- Bezel feel. Count the clicks, listen for back play, and check the lume pip is centered at 12.
- Dial printing. Replicas run fat or thin on the brand text. Genuine printing is crisp at arm's length.
- Hands. The syringe shape should be sharp, with flat lume fill rather than a domed blob.
- Caseback. Engraving depth is shallow on most replicas, and rotor decoration rarely matches the real finish.
- Crown. Should be signed, thread smoothly, and take a consistent number of turns.
- Water resistance. Do not swim in a replica on faith. Have it pressure-tested or keep it dry.
- Lume. Charge both under a light and compare after 30 minutes. Cheap lume fades fast.
- Strap and lugs. 23mm is an odd size, so check the sailcloth or NATO hardware feels solid.
Sizing and daily wear
43mm with long lugs wears bigger than the number suggests, and it will overhang a 6.5-inch wrist. If that is you, the 38mm Bathyscaphe ref. 5100 is the better shape to look at, in replica or otherwise.
Questions to ask a seller
Ask which movement is inside, what the measured power reserve is, whether the bezel insert is ceramic or coated metal, what the lug width is, and whether the watch has been pressure-tested. A seller who answers all five without hedging is worth your time. One who only sends photos is not.
Bottom line
Judge a fake Fifty Fathoms 5000 by the movement, the bezel, and the dial, in that order. Spec sheets are easy to copy. A 120-hour reserve, a smooth unidirectional bezel, and clean printing at 4:30 are not.