Short answer

A watch sold as "fake IW323759" or "first copy IW323759" is a replica. IWC does not make or sell first copy watches. The string IW323759 is not the form IWC uses. IWC prints IW plus four digits, a hyphen, then two digits, so the same watch would read IW3237-59. Sellers who write the number as one block of digits copy text from a listing, not from a caseback.

What the number means

IW3237 is a case family in the IWC line. The final two digits mark a variant inside that family. I could not find variant 59 of the 3237 family in public IWC material. Before you pay, ask IWC or an authorized service center to confirm that IW3237-59 exists and which case, dial, and caliber it uses.

Checks you can run in five minutes

  • Caseback. Genuine engraving has even depth and sharp edges. Replica engraving looks shallow and rounded under a phone macro lens.
  • Serial number. Look for 6 to 8 digits. The same number should appear on the caseback and on the warranty card or papers.
  • Screw-down crown. It should take 2 to 3 full turns to seat. A crown that seats in half a turn points to a cheap tube.
  • Date change. The date should flip within a few minutes of midnight. A date that drags across 20 minutes sits on a low-grade movement.
  • Lume. Charge the dial under a lamp for 30 seconds, then check in a dark room. Uneven patches or a weak glow point to a replica dial.
  • Weight. Put the watch on a kitchen scale and write the number down. Compare it with the same model in a published owner review.

Points where replicas fail

  • Case finish. Genuine IWC cases have crisp lines between brushed and polished surfaces. Fakes show soft or rounded edges.
  • Bracelet fit. End links should sit flush against the case with no gap and no rattle.
  • Bezel action. The click or the inner bezel turn should feel dry and even, with no backlash.
  • Crystal. Sapphire with an inner anti-reflective coating. Fakes show heavy reflections or a blue tint.
  • Movement. Replicas use unbranded or cloned movements. Rotor engraving is shallow, and the finish under a loupe shows tool marks.

Price check

Steel IWC dive watches from the 2000s sell used in the low thousands of US dollars. Listings at $150 to $400 with "first copy" or "mirror" in the title are replicas. No genuine IWC sells at that level.

If you already bought one

Get a written opinion from a watchmaker or an IWC service center. Keep the listing, photos, and messages. If you paid by card, open a dispute with the card issuer and attach the written opinion.

What I could not confirm

Public records do not show a variant 59 in the IW3237 family. Treat any claim about that reference as unverified until IWC confirms it.