A 45mm fake Fifty Fathoms copies the Blancpain Fifty Fathoms Automatique, reference 5015. The genuine case measures 45mm across, about 15.4mm thick, and takes a 23mm strap. Blancpain rates the watch to 300m. Replica cases match those numbers on paper. What changes is the movement and the finish.
Short Answer
Most 45mm replicas run an ETA 2824 clone or a Seagull movement under a decorative plate shaped like the Blancpain caliber 1315. The real 1315 has three mainspring barrels and a 120-hour power reserve. A clone gives about 38 to 42 hours. Case diameter, dial layout, and bezel markings can come close. Power reserve, rotor finish, and water resistance do not.
Numbers to Compare
- Case diameter: 45mm on both.
- Thickness: about 15.4mm genuine; replicas measure 15.5mm to 16.8mm in listing photos and caliper shots.
- Lug width: 23mm.
- Water resistance: 300m factory rating genuine. Replicas carry no rating you can trust.
- Crystal: sapphire on both, with inner anti-reflective coating.
- Bezel insert: sapphire on the 5015. Replica inserts use sapphire, ceramic, or mineral glass.
- Movement: caliber 1315, 120 hours. Clone: 38 to 42 hours.
- Caseback: several 5015 references use a solid back. A display back on a 45mm replica points to a wrong case.
Tells on the 45mm Case
Case thickness is the first check. Extra height comes from a spacer ring around a smaller movement. Look at the gap between the caseback edge and the wrist.
Fake Fifty Fathoms 45mm Design
Second check is the bezel. Turn it and feel the click spacing. Look for back play and for a gap between insert and case. Genuine sapphire inserts sit flush.
Third check is dial printing. The wordmark and the model text should show sharp edges at 10x magnification. Replica printing shows rounded corners and uneven spacing between the two lines.
Fourth check is lume. Both use Super-LumiNova type pigment. Replica lume fades in 20 to 30 minutes. Genuine lume holds a glow for hours.
Fifth check is the crown. It should screw down with two turns and carry an engraved logo. Threads that bind or skip show a cut case.
Movement Checks
Ask for a movement photo. A clone 1315 plate hides a base movement. The rotor on the clone spins with a rattle. The genuine rotor runs quiet. Winding feel differs too: the 1315 has three barrels and a long, even take-up. A clone feels stiff after 20 turns.
Timekeeping checks: a clone 2824 runs plus or minus 20 seconds a day out of the box. Regulation brings that to plus or minus 10 seconds. A 1315 runs inside plus or minus 5 seconds.
Price Bands
Low band: $80 to $150. These use a mineral crystal and a printed dial. Middle band: $200 to $450. These add a sapphire crystal, a sapphire or ceramic bezel insert, and a decorated movement. High band: $500 to $900. These use a 1:1 case, a clone 1315 plate, and matched lume. Bands shift with seller and batch.
Water Resistance
Do not dive with a 45mm replica. Gaskets vary by batch. A $20 pressure test at a local shop tells you the real limit. Most replicas pass 3 ATM. Few pass 10 ATM.
Questions for the Seller
- Which factory and batch number?
- Case thickness in millimeters, measured with calipers?
- Movement model and power reserve in hours?
- Bezel insert material?
- Crystal material and coating?
- Lume pigment source and glow duration?
- Return window and payment method?
Unknowns
Batch specs change without notice. Sellers reuse factory names. Thickness photos often omit the crystal dome. Power reserve figures come from the seller, not from a bench test. Confirm each number before you pay.