Short answer
A fake IW329163 is a counterfeit copy of the IWC Aquatimer Automatic reference IW329163, a stainless steel dive watch built on the 42 mm Aquatimer case. Genuine examples have deep, sharp caseback engraving with a matching reference and serial, clean dial printing with even spacing, a bezel that turns with firm and consistent clicks, and a decorated rotor visible through the display back. Most counterfeits fail on caseback depth, bezel feel, date alignment, and movement finish rather than on the overall silhouette, which can look close in photos.
What you need
- Clear photos of a known genuine IW329163, plus the official spec sheet for your production year
- A 10x loupe
- Digital calipers
- A kitchen or postal scale that reads in grams
- A bright, diffused light source
How to check an IW329163 for authenticity
- Photograph the caseback in flat light and write down the reference and serial exactly as engraved.
- Measure the case across the bezel and the lug width with calipers, then compare the numbers to the spec sheet for that reference.
- Weigh the watch head on the scale and note the figure, since counterfeit cases often use less material than the original.
- Examine the dial print through the loupe and check the weight and thickness of every letter in the IWC wordmark and the depth rating text.
- Look at the date aperture and confirm the numerals sit centered, with no tilt or mismatched font.
- Rotate the bezel through a full turn and listen for even clicks, since loose or gritty action points to a copy.
- Unscrew the crown and feel the thread engagement, then wind the movement and check that the rotor spins without scraping.
- View the movement through the display back and inspect the rotor engraving, Geneva stripes, and screw heads for tool marks.
- Charge the lume under a lamp for 30 seconds and compare the glow color and fade time against reference photos.
- Check the clasp, end links, and any caseback stamps for shallow or filled-in lettering.
- Compare the warranty card, booklet, and box against the serial and reference on the case.
- Have an IWC service center or an independent watchmaker confirm the serial before you buy or sell.
What counterfeiters usually get wrong
- Caseback engraving is stamped and shallow instead of cut deep with crisp edges.
- The reference and serial formats do not match the production year.
- Bezel action is loose, with uneven spacing between clicks.
- Date fonts are too wide or the window sits off center.
- Rotor decoration is printed or laser-etched rather than applied with real texture.
- Crown threads feel rough and the crown guards sit too thick or too thin.
Buying and resale notes
Ask for a movement photo, a caseback photo, and the service history before you commit to any IW329163. A seller who will not provide these has answered your question. On the resale side, an authenticity confirmation from IWC adds real value, so keep the paperwork with the watch. If you already own a watch you suspect is a copy, a watchmaker can open the case and confirm the calibre in minutes, and that report is worth more than any online opinion.