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The IW329105 is an IWC Aquatimer Automatic, a 42mm steel dive watch built around an inner rotating dive scale rather than an outer bezel. That single design choice decides everything about buying it as a replica. Copies that get the inner scale right, with a crisp ratchet, correct printing and a dial that sits flat under the crystal, are worth the money. Copies that only reproduce the dial print are not. Before you send payment, ask the seller for dated macro photos of four things: the inner bezel ring at the 12 and 6 positions, the crown threads with the crown pulled out, the caseback engraving, and the clasp stamping. A seller who cannot produce those photos has never handled the watch they are listing.

What to look for

Case and inner bezel

The Aquatimer case is a mix of brushed flanks and polished bevels, and the transition between the two should be a straight, sharp line. Run a fingernail along the lug edges. A soft, rounded edge means the case was over-polished after machining. The inner dive scale must index cleanly at every five minute mark, and it should not drift when you tap the case against your palm. Check that the triangle at zero lines up with the 12 o'clock index. Misalignment here is the most common flaw on this reference and it cannot be fixed later.

Dial, hands and lume

Look at the applied indices under raking light. They should cast a small, even shadow and sit parallel to the dial. Crooked markers show up in photos once you know to look for them. The lume fill should be flat and level with the metal frame, not domed or spilling over. On the hands, check that the sweep is not too fat and that the tip of the minute hand reaches the minute track without touching it. Date wheels should be white with black print and sit centered in the window.

Crystal and movement

The original uses a sapphire crystal with anti-reflective coating on the underside. Many replicas skip the coating, and the dial then reads flat and grey instead of deep black. Ask the seller to photograph the dial at a 45 degree angle with a light source nearby. On the movement side, a 28,800 vph automatic with hacking and a smooth, quiet rotor is the baseline. Shake the watch near your ear. A rattling rotor or a gravelly wind points to a low grade unit that will not hold time.

Bracelet and clasp

Check the link count against the reference, the taper toward the clasp, and the fit of the end links against the case. Gaps at the lugs are visible in real life even when photos hide them. The clasp should close with a firm, single click and the safety catch should not need force. Screw-in links are a good sign. Push pins are acceptable but check that none sit proud of the link surface.

Sensible parameter bands

  • Case diameter: 41.8mm to 42.3mm. Anything outside that is a different case, not this reference.
  • Thickness: about 14mm including the domed crystal.
  • Weight on the full bracelet: roughly 170g to 190g. A light watch means a thin case or a hollow bracelet.
  • Beat rate: 28,800 vph, which shows as a smooth sweep rather than a visible tick.
  • Water resistance: treat any claim above splash resistance as marketing. Ask what the caseback gasket actually is.

Pitfalls to avoid

  • Factory render images instead of the seller's own photos. Renders hide every flaw you are trying to inspect.
  • Listings that use the reference number but show a different Aquatimer generation.
  • Mineral glass sold as sapphire. Ask for a scratch test photo or skip the listing.
  • Inner bezel printing that is too thick. The dive scale numerals should be fine and evenly spaced.
  • No pre-shipment QC photos. Insist on them, with a timestamp, or walk away.
  • Rushed sizing. Ask the seller to size the bracelet to your wrist before shipping so you are not hunting for spare links later.

FAQ

Is the IW329105 the same watch as the Aquatimer Automatic 42?

Yes. The reference sits inside the 42mm Aquatimer Automatic family, so case dimensions, dial layout and bracelet design carry across. Use photos of any 42mm Aquatimer Automatic as your comparison set.

Should I pay more for a claimed Swiss movement?

Only if the seller can show the movement through the caseback or with the back removed. Otherwise a well finished Japanese or Chinese automatic at 28,800 vph is the safer buy, because parts and servicing are easier to source.

Can I swim with it?

Do not assume so. Have a watchmaker pressure test it first, and understand that a failed test is common on this tier. For pool use, a tested case with fresh gaskets is the minimum.

How do I verify the inner bezel alignment remotely?

Ask for two photos: one with the scale at zero and one rotated a quarter turn. Compare the triangle position to the 12 index in the first shot and to the 3 index in the second. Both should line up exactly.