A fake Fifty Fathoms 45mm is a replica of Blancpain's 45 mm Fifty Fathoms diver, built with a stainless steel case that mimics the original's profile and a cloned or generic automatic movement inside. The case sits close to 45 mm across and about 15 mm thick, so the watch wears large, and the real quality differences show up in the bezel insert, dial printing, movement finish, and how well the case is sealed.

What the 45mm Measurement Means on a Replica

The genuine 45 mm Fifty Fathoms is a big dive watch, and replica makers use that number as a selling point. Measured diameter on a fake can land anywhere from about 44.5 mm to 45.5 mm depending on the case supplier, and thickness often runs 14.5 mm to 16 mm. Lug width is usually 23 mm, which limits how many aftermarket straps drop straight on.

Because the case is wide and the crystal domed, wrist presence is closer to a large sports watch than a slim diver. If you have a wrist under about 6.75 inches, the 45 mm case overhangs the edges on most straps.

Movements Found Inside a Fifty Fathoms 45mm Replica

The original runs Blancpain's in-house calibre 1315 with a long power reserve and three series-coupled barrels. No replica reproduces that architecture. What you actually get falls into a few groups:

  • Asian clone of the ETA 2824-2 or 2836-2. Beats at 28,800 vph, hacks, hand-winds, and is easy for any watchmaker to service. The 2836 adds a day or date complication that the original does not have.
  • Chinese-made equivalents such as the Seagull ST21 family. Similar footprint to the 2824, generally reliable, sometimes with a smoother winding feel than the cheapest clones.
  • Decorated movements. Engraved rotors, striped bridges, and blued screws meant to look like a finished in-house calibre. The decoration hides a standard automatic underneath, and some decorated plates reduce the service access a watchmaker needs.

Ask for a timegrapher reading rather than a stock photo. Rate, beat error, and amplitude tell you more about the movement than any factory name.

Bezel, Dial, and Case Details That Separate the Tiers

  • Bezel insert. The original uses a domed sapphire insert. Cheaper fakes use mineral glass or acrylic that scratches and yellows.
  • Lume. Good versions use a proper grade of luminous compound on bezel and dial. Weak versions glow green and fade within minutes.
  • Dial printing. Check the thickness and spacing of the text, the font of the numerals, and whether the date window sits centered.
  • Crystal and coating. A sapphire crystal with inner anti-reflective coating cuts glare. Uncoated sapphire looks flat and gray.
  • Caseback. Engraving depth, spacing, and the reference numbers should match the era of the watch being copied.
  • Crown and guards. Threads should engage smoothly with no grinding, and the guards should not rub the crown.

Water Resistance: Assume Nothing

Most listings for a fake Fifty Fathoms 45mm claim 300 m. That figure comes from the original's rating and copies the marketing, not the build. Gaskets in budget replicas may be dry, pinched, or missing. A watchmaker can pressure test a case for a small fee, and many will add silicone grease to the seals at the same time. Until a case has passed a test, keep it away from showers, pools, and salt water. Even after a pass, a high-tier rating is realistic for splashes and rain rather than diving.

Weight, Thickness, and How It Wears

Steel replicas land in the 110 to 150 gram range on a strap, which feels close to the original. Titanium versions feel noticeably lighter. The 15 mm thickness plus a domed crystal means the watch sits high on the wrist and catches sleeves. A curved-end rubber strap or a sailcloth strap with the right 23 mm width keeps the head from sliding around.

Price Tiers at a Glance

  • Entry tier. Mineral bezel insert, generic movement, painted dial markings, no meaningful water resistance.
  • Mid tier. Sapphire crystal, better lume, a clone 2824 or 2836, decent case finishing.
  • Upper tier. Sapphire bezel insert, sharper dial print, closest case dimensions to the 45 mm original, and a movement that survives regulation.

Checklist Before You Buy

  1. Ask for caliper photos of the case diameter and thickness.
  2. Request a timegrapher photo or video with the movement running.
  3. Get close-ups of the bezel at 12 o'clock to check alignment.
  4. Confirm the bezel insert material in writing.
  5. Check that the lug width is stated as 23 mm so straps fit.
  6. Budget for a pressure test and a service if the watch runs poorly.

Short Answers to Common Questions

Does a fake Fifty Fathoms 45mm use the same movement as the original?

No. The original uses Blancpain's in-house calibre with a long power reserve. Replicas use cloned or generic automatics, and the caseback decoration is cosmetic.

Is a 45 mm replica too big for most wrists?

It wears large. The case is wide and thick, so it suits wrists around 7 inches and up. Smaller wrists do better with a 42 mm or 40 mm version of the same design.