Quick answer
A fake IW371470 tends to fail on four things: the caseback engraving, the movement visible through the display back, the dial printing, and the weight. Genuine IWC Portugieser Chronograph watches in the 3714 family carry sharp engraving with a serial that matches the reference, a finished movement with the correct caliber text, and a case that feels heavier than the copy. If two or more of those checks fail, walk away.
What the genuine reference should show
Before you inspect anything, pull up the official spec sheet for the exact reference. IWC built the Portugieser Chronograph across many production runs, so small details change between them.
- 41 mm stainless steel case, about 13 mm thick, polished bezel with brushed flanks
- Sapphire crystal front and back, with anti-reflective coating on both faces
- Chronograph with a 30-minute counter, a running seconds subdial, and a date aperture
- Applied numerals and leaf-shaped hands, not printed markers
- Movement: older 3714-series watches use the 79350 (a reworked Valjoux 7750), later versions use the in-house 69355
Step-by-step inspection
- Compare the dial layout against official photos for the reference. Count the subdials, check where the date sits, and compare the thickness of the numerals.
- Turn the watch over and read the caseback. Genuine engraving is shallow and crisp, with the reference number, serial number, and the IWC name in the correct typeface.
- Run the chronograph. Start, stop, and reset the pushers. A genuine 7750-based movement snaps back to zero without hesitation. Copies with quartz or low-grade mechanical movements feel mushy or the seconds hand stutters.
- Look through the display back with a loupe or a phone macro lens. Check for Geneva stripes, blued screws, and the caliber number on the rotor or bridge. Replicas often hide an unrelated movement behind a decorated plate.
- Weigh the watch on a kitchen scale and compare the result to a known genuine example. Stainless steel Portugieser Chronographs have a solid heft that plated brass copies lack.
- Angle the crystal under a lamp. The anti-reflective coating throws a faint blue or purple sheen. Many copies ship with uncoated glass.
- Inspect the strap and buckle. Real alligator has irregular scale patterns. Embossed cowhide shows a repeating print. The IWC folding clasp should have crisp engraving and smooth action.
- Verify the serial number with IWC or an authorized dealer, and ask for service history if the seller has papers.
Red flags
- Price far below the current secondhand range for the reference
- Blurry photos, or no photos of the caseback and movement
- The same serial number appearing in other listings
- A seller who refuses a video call or third-party authentication
- A watch sold as new with no box, papers, or warranty card
- Flat dial printing or misaligned subdial rings
Where first copy buyers get caught
People shopping for first copy watches understand the difference between a replica and a genuine IWC. The problem starts when a listing claims genuine status and shows replica photos, or when a reseller mixes the two in one inventory. If you buy a copy, expect generic caseback text, a substitute movement, and finishing that sits below the original. That is normal for the category. What is not normal is a seller charging genuine money for a copy. Ask which movement is inside, ask for the reference and serial in writing, and keep those answers before you pay.
Authentication checklist before you pay
- Request dated photos of the front, back, movement, clasp, and both case flanks.
- Get the serial and reference numbers in text, not only in a photo.
- Pay with a method that allows a dispute.
- Have a watchmaker open the case inside the return window.
- Save the listing screenshots and messages until the return period ends.