The short answer
A replica IW329013 is a copy of IWC's Aquatimer Automatic, a 42mm steel dive watch with an internal rotating bezel. Good copies exist, bad ones are everywhere, and the price gap between them is smaller than most people expect. If you want one that survives daily wear, budget for the middle of the market and check four things before you pay: the bezel action, the movement inside, the crystal coating, and how the lugs meet the strap. Everything else is cosmetic and fixable.
What the IW329013 actually is
The reference sits in IWC's Aquatimer family, the dive line that got a full redesign around 2014. The case is 42mm of stainless steel, the crystal is sapphire, and the party trick is the internal bezel: a rotating dive scale that lives under the glass instead of on top of it, driven by a crown at two o'clock. IWC calls its clutch mechanism the SafeDive system, which lets the bezel turn freely in both directions but locks it to the outer crown so it cannot be knocked out of position by accident.
That bezel is the whole point of the watch. It is also the single hardest thing to copy well, which makes it the best filter you have when shopping.
Note that reference numbers get garbled in listings all the time. Confirm the dial layout, case size, and crown position against IWC's own spec sheet before you commit, because sellers mix up Aquatimer references constantly and a photo of a different model is a warning sign on its own.
Where replicas fall apart
The internal bezel
Turn the two o'clock crown slowly. A decent copy moves the scale with a light, even resistance and stops where you stop. A poor one feels gritty, has slack before the scale engages, or lets the triangle drift a few degrees off twelve when it seats. Check alignment against the dial markers, not against the case, because the case can be rotated in photos.
The movement
Most cheap Aquatimer copies run a 21-jewel Asian automatic with a rough rotor and a sweep that stutters. Better ones use a 2824 or 2892 clone, and the top tier uses a Swiss ETA. Ask what is inside and ask for a photo of the movement with the caseback off. If the seller will not show you, that answers the question. The genuine watch uses IWC's caliber 30120, which is built on a Sellita SW300 base, so a 2892-style clone is the closest structural match.
Crystal and coating
The real watch has sapphire with anti-reflective coating on both faces, which makes the dial look like it is floating. Many copies coat only the outside, or use a coating with a blue cast that shows up under indoor light. Tilt the watch under a lamp and look for a purple or green sheen across the whole dial. Flat, colorless glass on a dive watch is usually mineral.
Lume and dial print
Weak lume is the most common tell after dark. Genuine Aquatimer hands and indices glow evenly and fade slowly. Copies often glow hard for ten minutes and then die, or glow unevenly across the hour markers. On the dial, check that the text is crisp under magnification and that the date sits centered in its window.
Price tiers, honestly
- Under $300: mineral glass, 2813 movement, wobbly bezel. Fine as a lookalike, not as a watch.
- $350 to $600: the sweet spot. Sapphire, 2824 clone, decent brushing and a bezel that actually engages.
- $700 and up: Swiss movement, sharper case finishing, closer lume and crown feel. Worth it only if you plan to keep it.
Red flags when shopping
- No movement photo, or a photo that is clearly a stock image.
- Listings that claim 300m water resistance. Treat any copy as splash resistant only.
- One photo of one angle. Ask for the caseback, the crown side, and a close shot of the bezel triangle.
- Prices far below the tier. A $180 watch with "Swiss ETA" in the title is neither.
Living with it
Have a watchmaker pressure test it before you swim, and do not assume the gaskets are fresh. Keep the two o'clock crown screwed down when you are not using the bezel. The rubber strap on most copies is stiffer than the original, so budget for a replacement if comfort matters to you. Get the movement serviced every few years and the watch will outlast your interest in it, which is more than most people can say about a cheap copy.