A replica IW329105 is worth buying only when it copies four things: the 42 mm case, the outer bezel that drives the inner dive scale, a 28,800 vph automatic with a clean sweep, and tidy dial printing. Anything less is a generic dive watch with a logo glued on. Run the checks below before money changes hands.

What the reference IW329105 actually is

The IW329105 sits in the IWC Aquatimer Automatic line. It uses a 42 mm steel case, a 300 m water resistance rating, sapphire crystal, a screw-down crown, and IWC's SafeDive bezel, where the outer ring turns the inner dive scale so the timing ring cannot be knocked out of position. Inside is the calibre 30120, a 4 Hz automatic with roughly 42 hours of reserve. Knowing these numbers gives you a fixed yardstick; a replica that misses them is not a replica of this watch.

How to check a replica IW329105 before you buy

  1. Ask the seller for a caliper photo of the case across the lugs. Accept 41.8 to 42.2 mm and walk away from the 44 mm "close enough" cases.
  2. Ask for the case thickness. This reference sits near 14 mm; a 16 mm slab wears wrong on the wrist and signals a different case set.
  3. Request a video of the bezel being turned. The outer ring must move the inner scale with it, click through detents, and show no side-to-side play.
  4. Get one straight-on dial photo at maximum zoom. Check that the 12 o'clock markers meet in line with the crown and that the date sits centered in its window.
  5. Ask which movement is fitted. A Miyota 9015 or a 2824-family clone is acceptable; "Swiss movement" with no calibre name is not an answer.
  6. Ask for a ten-second video of the seconds hand. Count the beats; at 28,800 vph you should see eight small steps per second.
  7. Confirm the strap interface. The genuine watch uses a quick-change system, so ask whether the replica has it or standard spring bars, and get the lug width.
  8. Ask whether the watch has been pressure tested. A 300 m claim with no test result is marketing, not a specification.

Red flags

  • Stock catalog renders instead of photos of the actual unit in hand.
  • A bezel that turns but leaves the inner scale still, which means the linkage is decorative.
  • Printed indices instead of applied metal markers.
  • No stated movement, or a calibre name that does not exist.
  • Sellers who refuse a timestamped photo of the caseback.

After the watch arrives

  1. Inspect the case flanks under a lamp for sharp lug edges and uneven brushing.
  2. Charge the lume with a phone torch for 30 seconds and compare brightness across all markers.
  3. Set the time, wait 24 hours, and note the deviation against a reference clock.
  4. Take it to a local watchmaker for a pressure test before it goes near water.
  5. Check the crown threads by unscrewing and reseating three times.

What no replica gets right

Case finishing at the lug curves, lume endurance, bezel spring tension, and bracelet tolerances are the usual gaps. Treat a replica as a look-alike, not a dive instrument, and never dive with one. It is also not a genuine watch, so do not resell it as one.