A fake Fifty Fathoms Tritium 5015 is a replica of the Blancpain Fifty Fathoms reference 5015, a 45 mm modern dive watch that uses Super-LumiNova on its dial and hands, not tritium. The name mixes two eras: tritium lume belongs to vintage Fifty Fathoms dials, while reference 5015 arrived in 2007. Understanding that gap tells you a lot about how a specific replica was built and what a seller is really describing.

Why "Tritium" and "5015" Do Not Belong Together

Swiss watchmakers used tritium paint on dive watch dials from the 1960s until the late 1990s, when the industry moved to safer, non-radioactive luminous compounds. Vintage Fifty Fathoms examples from that period often carry tritium and show the warm, creamy patina collectors chase.

Reference 5015 sits on the other side of that timeline. It is a modern production model, so its dial is luminous with a modern compound that charges under light and fades in darkness. A genuine 5015 has no reason to carry tritium markings, and neither should a well-made replica.

How Tritium Dials Are Marked

Tritium dials give themselves away with printed codes near the bottom edge of the dial, usually under the 6 o'clock position. Look for:

  • T SWISS MADE or T SWISS T: a T on both sides of the Swiss marking
  • SWISS T < 25: a tritium code tied to low radiation output
  • Aged lume plots in a tan, pumpkin, or coffee tone rather than bright white or pale green
  • Hands that match the dial's patina instead of looking newer

If a listing calls a watch a Fifty Fathoms Tritium 5015 and shows a modern dial stamp with no T code, the word "tritium" is decoration. Many replica makers use tinted paint to imitate patina, which is common and easy to spot once you know the codes.

What to Check on a Replica 5015

  • Dial print: the maker's logo, depth rating, and font weight should be crisp, not blurry or uneven.
  • Bezel action: a 120-click unidirectional bezel with a firm, even feel and proper alignment at 12.
  • Case size and profile: the 5015 wears large at 45 mm, so proportions matter more than the numbers on paper.
  • Crystal: domed sapphire with weak reflection and a clean edge at the case.
  • Lume behavior: modern compound glows after a light charge; painted faux patina does not.
  • Caseback engraving: deep, sharp lettering rather than shallow laser etching.

Questions to Ask Before You Buy

  1. Which reference is the replica based on, and does the dial marking match that reference?
  2. Is the lume described as tritium, or is it simply tinted to look aged?
  3. Which movement is inside, and how long is it rated to run on a full wind?
  4. Are the photos of the actual watch or stock images from the factory?

The Short Answer

Treat the phrase "Fifty Fathoms Tritium 5015" as a styling label, not a specification. Reference 5015 is a modern dive watch with modern lume, so any tritium cue on a replica is there to imitate vintage character. Judge the piece on dial print, bezel feel, case finishing, and the honesty of the listing instead of the marketing words.