Short answer

A replica IWC Portugieser chrono 42mm is a copy of the Portugieser Chronograph Classic, the IW3903xx family IWC launched in 2013. It is the only Portugieser chronograph with a 42mm case. The 40.9mm IW3714 and the 41mm IW3716 are separate references, so when a listing calls a 41mm watch a 42, you already know something is off.

It is also one of the harder Portugiesers to copy with conviction. The genuine watch runs IWC's in-house calibre 89361, which stacks elapsed hours and minutes into a single totalizer at 12 o'clock. Cheap movements cannot do that, so they copy the layout and hope nobody presses the pusher.

The genuine watch, in numbers

  • Case: 42mm stainless steel, about 14.3mm thick
  • Movement: IWC calibre 89361, automatic flyback chronograph, roughly 68 hours of power reserve
  • Dial: combined hour and minute chronograph counter at 12, running seconds at 6, date at 3
  • Glass: sapphire front and back, antireflective coating on both faces
  • Water resistance: 30m, which is rain and handwashing and nothing more
  • Strap: alligator leather on a folding clasp, plus gold-cased versions

The Chronograph Classic is no longer in the current catalog, so nearly everything you see is secondary market stock. Steel examples trade below the original retail, which sat near $9,000.

What gives a copy away

Start with the chronograph. Press the top pusher and watch the counter at 12. The real 89361 records hours and minutes in one subdial. Most copies manage a 30-minute counter at best. Ask any seller for a short video of the chrono running and resetting. If they will not send one, that answers the question.

Thickness comes next. A 42mm chronograph case carries a lot of movement, and clone movements are not thin. The genuine article is about 14.3mm. Copies land from 14.5mm to 16mm and sit high on the wrist. A listing that claims 13mm on a chronograph is mistaken or lying.

Then the small things. The date window at 3 should be crisp, with a font that matches the dial print. Look at the lugs: the originals curve down and inward, and the case flanks are brushed while the bezel top is polished. Plenty of replicas polish the whole case because it photographs well. Dial text should be sharp under a loupe, with even spacing between the wordmark and the line beneath it.

Movements you will actually find inside

Two families dominate. The first is the Seagull ST19, a hand-wound column wheel chronograph derived from an old Venus design. It looks decent through a display back and is cheap to service, but you wind it every day and the subdial layout rarely matches. The second is an Asian 7750 variant with a modified date wheel or an added module. It is automatic, heavier, and thicker. Neither one approaches the finishing or the 68 hour reserve of the 89361, and many watchmakers will turn the job down when something breaks.

Buying checklist

  • Confirm the size first. 42mm means Chronograph Classic, not the 41mm IW3716.
  • Ask for photos with a ruler or calipers across the case, not just wrist shots.
  • Get a running chronograph video that includes a reset.
  • Look at the case back photo. The 89361 is a well finished movement, so a plain undecorated rotor behind a display back is an easy tell.
  • Check what ships with it. A lot of copies arrive with a stiff strap and a loose clasp.

Legal side, if you are in the US

Counterfeit watches cannot be legally imported into the United States. CBP seizes them, and you usually do not get your money back from the seller. Selling them is a bigger problem: trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320, carrying prison time and fines, plus civil liability to the trademark owner. Wearing one is not the same as moving a pallet of them, but the risk curve is not flat. Add no warranty, no IWC service, and a fair chance your local watchmaker says no.

Bottom line

If you want the 42mm Portugieser look, know that you are buying the silhouette and not the watch. The case shape and the dial can get close. The 89361's combined totalizer, the 14.3mm profile, and the finishing under the display back will not. Work out which of those you actually care about before spending anything, and read the legal section twice if you are stateside.