Short answer
A fake Fifty Fathoms GMT is a replica of Blancpain's dive watch with a 24-hour hand. High-grade replicas sell for $280 to $650. Low-grade versions sell for $60 to $150. A genuine Fifty Fathoms GMT runs $16,000 to $22,000 at retail. Replicas copy the case shape, dial layout, and bezel. They do not copy the movement, the sapphire bezel insert, or the case finishing.
The genuine watch
Blancpain shipped the first Fifty Fathoms in 1953 for French combat divers. The line uses 300 m water resistance, a screw-down crown, and a unidirectional bezel. Modern Fifty Fathoms cases measure 42.3 mm to 45 mm. The GMT version adds a fourth hand that reads against a 24-hour scale, so the wearer tracks a second time zone.
Blancpain fits in-house automatic calibers to this line. Power reserve on several references is 120 hours. The bezel insert is sapphire crystal with lume under the surface. Reference numbers, case sizes, and dial colors change by year, so check any specific reference against the brand site or an authorized dealer.
What replicas copy
Replica makers work from photos and, in some cases, a borrowed genuine watch. Most units use a 45 mm stainless steel or titanium case, a sapphire crystal, and a printed dial. Details shift by factory and by batch.
- Case: 45 mm wide, 15.5 mm to 16.5 mm thick.
- Bezel: coated mineral or glass on cheap units. Some mid-tier units use sapphire.
- Dial: printed text, applied markers, GMT hand. The weight of the Blancpain script is the most common error.
- Caseback: solid steel or a display back, depending on the model being copied.
Movements in replicas
Three movement families show up in these watches.
- Miyota 9015 with a bolt-on GMT module. 24 jewels, 28,800 vph, about 42 hours of reserve. This is the base in the $280 to $450 range.
- Asia ETA 2836-2 or a Sea-Gull copy with a GMT gear set. Louder rotor, weaker finishing, lower price.
- Decorated movements with bridge plates stamped to look like a Blancpain caliber. The plate hides a stock base. Engraving depth is the tell.
None of these match a Blancpain in-house caliber. Replica reserve runs 38 to 45 hours against 120 hours on several genuine references.
How to spot one
- Bezel insert material. Sapphire looks like glass and passes light. Mineral and acrylic do not.
- Lume. Charge the watch under a lamp. Super-LumiNova glows even and fades over hours. Replica lume is blotchy.
- Crown action. Genuine threads are cut clean and seat in four to five turns. Replicas grind after three.
- Date font. Compare numeral shape and the edge of the window.
- Weight. Titanium versions sit near 100 g on a strap. Steel sits near 140 g. Replicas land 10 g to 20 g off.
- Movement. Look at the balance wheel and the screw heads under a loupe. Genuine parts show beveled edges.
- Serial and reference numbers. Mismatched stamps are a flag.
Price tiers
- $60 to $150: mineral glass, quartz or low-grade automatic, plated bezel, 30 m resistance at best.
- $180 to $400: Miyota or Asia ETA, sapphire crystal, cleaner dial printing, 3 ATM to 5 ATM.
- $450 to $650: GMT module, sapphire bezel, better case work, claimed 300 m rating.
A service on a replica costs $120 to $200 at an independent watchmaker. Many shops refuse replica work.
Legal status in the US
Counterfeit watches carry trademarks owned by Blancpain and its parent group. Import into the US violates 19 U.S.C. § 1526. U.S. Customs and Border Protection can seize and destroy shipments. Selling counterfeits can bring civil damages and criminal charges. Buying one for personal use carries lower risk, but the item can be seized in transit and the payment is not recoverable.