The short answer
A fake IW329105 is a counterfeit of the IWC Aquatimer Automatic 42, a 42 mm steel dive watch with an internal rotating bezel and a screw-down crown. The reference sits inside IWC's Aquatimer Automatic 42 family, which has been in and out of the catalog since the mid 2010s. Fakes of it come in two broad tiers: low-grade quartz and budget automatic copies that sell for well under $100, and the higher-tier clones often marketed as "first copy" or "super clone" versions in the $300 to $600 band.
The second tier is where the confusion lives. Those watches photograph well. In the hand, the gaps show up fast, and almost all of them sit in the same places.
What the genuine reference actually is
Before you judge a copy, know the target. The Aquatimer Automatic 42 in steel runs a 42 mm case, roughly 14 mm thick, with a sapphire crystal that has anti-reflective coating on both faces. Water resistance is rated to 300 meters. Inside is IWC's calibre 30120, an automatic movement with about 42 hours of reserve and a 4 Hz beat rate.
The bezel is the signature feature. IWC calls it SafeDive: an outer ring drives the inner bezel through a clutch, and the inner ring only moves counterclockwise. The numbers live under the crystal, not on top of it. That one design choice makes the bezel far harder to fake than a standard dive bezel, because the fake has to reproduce the gearing feel, not just the look.
The tells I check first
- Bezel action. A real one turns with a firm, damped click and the inner ring tracks the outer ring exactly. Fakes feel gritty, loose, or the two rings drift out of sync.
- Dial printing. Look at the "IWC" wordmark under a loupe or a phone macro shot. Genuine printing has crisp edges. Clones are usually slightly thick or slightly soft at the corners.
- Applied markers and lume. Markers on the original sit flush and even, with a consistent fill. Fakes often have a marker sitting a hair off center or lume that looks chalky.
- Date wheel. The font, the position in the window, and how it snaps over at midnight all matter. A slow, lazy flip is a tell.
- Crystal and reflections. Real double AR coating gives a faint blue-violet cast at an angle. Single-side or no coating looks flat and mirrors the room.
Movement and caseback
Open the back if you can, or ask for a movement photo. Clones for this reference typically run a Chinese automatic, an ETA 2824 clone, or a Sellita copy. They keep time, but finishing is the giveaway: rotor engraving is shallow, perlage is stamped rather than cut, and the bridge edges are unfinished.
Caseback engraving is where a lot of fakes fall over. Reference number, serial, and the IWC markings should be crisp and deep. If the serial repeats across listings from different sellers, that is not a coincidence.
Strap, clasp, and packaging
Rubber straps on the real watch have a specific smell and flex, and the keeper sits tight. Clone rubber is usually stiffer and thinner. On the folding clasp, check the spring tension and the engraving depth. Packaging is a poor test on its own, because boxes and papers are copied and sold separately, so never treat a box as proof of anything.
Water resistance, and the number fakes never reach
A 300 meter rating is a serious engineering claim. It depends on gasket quality, case machining, crown threads, and pressure testing. Clones are not tested to that standard and often leak at the first swim. Treat any replica as splash-resistant at best, regardless of what the caseback says.
Red flags when you are buying
- A price far below the secondary market for the reference.
- A seller who will not send macro photos of the caseback and crown.
- Stock photos only, or photos that match several other listings.
- Pressure to decide fast, or payment methods with no recourse.
If you are buying a replica on purpose, go in knowing what it is and what it is not. It will not hold value, it will not survive a dive, and it will not service like the real thing. If the seller claims otherwise, walk.
Legal reality
Counterfeit watches are illegal to sell in most countries, and customs agencies seize them. That does not stop the market, but it does shape how sellers operate, which is why returns and warranties tend to be vague. Factor that into any decision.