A fake Fifty Fathoms GMT is a replica of Blancpain's Fifty Fathoms GMT, a dive watch with a second time zone indicator, and most examples built in China copy the outer look well while giving themselves away in the bezel action, the 24-hour hand, the dial printing, and the movement. If you are trying to identify one or decide whether a replica is worth owning, the details below cover what actually changes between models.
What the Fifty Fathoms GMT Is Supposed to Be
The Fifty Fathoms is Blancpain's dive watch line, and the GMT version adds a fourth hand that tracks a second time zone on a 24-hour scale. The original package is a large stainless steel case, a rotating dive bezel, a screw-down crown, and a legible dial with luminous markers. A replica has to reproduce all of that at once, which is why the GMT variant is more demanding than a plain three-hand fake.
Why the GMT Version Is Harder to Fake
A three-hand dive watch fake only needs correct hands and a moving rotor. A GMT fake also needs:
- A fourth hand that sets and tracks a 24-hour scale correctly
- A date change that stays synchronized with the hour hand
- A bezel that lines up with the case at 12 o'clock
- Printing on the dial that does not sit crooked under magnification
Failures usually show up in the second and third points. Many budget replicas have a GMT hand that jumps out of position or a date that flips at noon instead of midnight.
The Tells: Case, Bezel and Crystal
Case and crown
Check the crown guards and the crown engraving. Genuine Blancpain models use a signed crown with crisp relief. Replicas often have shallow engraving, a crown that wobbles when unscrewed, or crown guards that look thicker on one side than the other.
Bezel and insert
Turn the bezel slowly. A real dive bezel clicks at consistent intervals and has almost no back play. Cheap fakes feel gritty, have uneven click spacing, or stop between positions. On sapphire insert versions, look at the edge of the insert where it meets the bezel ring, since that seam is where replicas most often show a gap.
Crystal and anti-reflective coating
Blancpain applies anti-reflective treatment to both sides of the crystal on many models, which creates a faint blue or purple tint at an angle. Replicas often coat only the outside, so the dial looks flatter and reflects more under indoor lighting.
Dial, Hands and the 24-Hour Hand
Read the text on the dial with a loupe or a phone macro shot. On a fake Fifty Fathoms GMT, the most common problems are uneven letter spacing, a logo that sits slightly off center, and a GMT hand whose arrow tip is too wide or too narrow compared with the hour markers. Lume is another quick test: charge the watch under a lamp, then compare the glow of all four hands with the dial markers. If the GMT hand glows a different color or fades faster, the parts came from different sources.
Movement Inside a Replica Fifty Fathoms GMT
Replica GMT watches from China generally use one of a few automatic movements: a modified 2836-style movement with an added GMT module, a Chinese-made automatic GMT caliber, or a basic low-cost GMT movement in the cheapest builds. The module type matters because it affects how the GMT hand sets.
- Independent GMT hand: the fourth hand moves on its own with the crown in one position, and the date stays linked to local time.
- Slaved GMT hand: the fourth hand follows the hour hand and cannot be set separately, which limits how useful the watch is.
- Quick-set date only: a sign the movement is a simple three-hand base with a decorative fourth hand.
Open the caseback or ask for a movement photo. Rotor decoration and engraved plates are common on replicas, but the engraving quality and the finish under the rotor tell you which tier you are looking at.
Water Resistance and Real Use
Replica dive watches should not be treated as dive watches. Gaskets, case tube threading, and caseback sealing on fakes vary from batch to batch, and a rating printed on a caseback is not a test result. If you swim with one, pressure test it first, and accept that a failure means water inside the movement.
Quality Tiers You Will See
- Budget tier: correct silhouette, wrong bezel feel, slaved GMT hand, hollow end links.
- Mid tier: solid bracelet, working GMT function, minor dial printing flaws.
- High tier: closer case proportions, sapphire insert, better movement finishing, still not a genuine watch.
Quick Checklist Before You Buy
- Confirm the GMT hand sets separately from the hour hand
- Check the date flips near midnight, not midday
- Look at bezel alignment and click consistency
- Request macro photos of the dial text and crown
- Ask which movement is inside and whether it has a GMT module
- Assume no meaningful water resistance until it is tested
Red Flags in Listings
Be cautious when a seller claims a replica is a genuine watch, uses photos taken from another listing, refuses close-up shots of the dial and movement, or advertises a Swiss movement with no photo of the movement itself. Any of those points is enough reason to walk away from a fake Fifty Fathoms GMT deal.