If you are searching for a fake IW371615, the version worth your money is the 41 mm two-register chronograph first copy with a correctly centered subdial layout, sapphire crystal, and pushers that start, stop, and reset with a firm click. I rank every option on four criteria: dial and subdial accuracy, case and bracelet finishing, chronograph action and movement type, and the small details on crystal, crown, and caseback. Boxes and papers come last, because they change nothing about the watch on your wrist. Note up front that a first copy is a replica, not a genuine IWC, and passing one off as real is fraud.
Dial and subdial layout
Portugieser Chronograph references in the 3716 group use a 41 mm case with two registers stacked vertically, so the spacing between the upper and lower subdials is the first thing a trained eye reads. Confirm the published layout for the exact reference you are comparing before you judge a copy.
Pros
- Better copies print crisp concentric rings inside each subdial, with numerals that stay legible at arm's length.
- Applied indices sit flat and throw a clean reflection; the date aperture is cut square and sized to the numerals.
- Hands reach the printed track instead of falling short or overshooting it.
Cons
- Budget copies drift off center, so one subdial sits closer to the case edge than the other.
- Printing looks flat and slightly fuzzy under magnification.
- Date fonts run too bold, and hands are chromed rather than properly polished.
Use case: ask the seller for a straight-on macro photo and a wrist shot, then draw an imaginary vertical line through both subdial centers. If that line wanders, skip the watch.
Case and bracelet finishing
Finishing is where a mid-tier first copy separates itself from a cheap one, and it shows in daylight rather than in photos.
Pros
- 316L steel cases with brushed flanks and polished chamfers catch light the way the original design intends.
- End links meet the lugs with no visible gap, and the bracelet articulates without stiffness.
- Clasp markings are engraved rather than stamped, which survives daily wear.
Cons
- Thin plating wears through at the clasp and caseback within months.
- Sharp lug edges and hollow end links that rattle.
- Case thickness creeps past spec once a thick movement and spacer ring are fitted.
Use case: if you wear the watch to an office and take it off at a desk, finishing quality matters more than the movement. If you wear it swimming, none of these copies are the right call.
Chronograph action and movement
Pros
- Quartz chronographs are inexpensive, accurate, and need almost no service.
- Mechanical chronograph movements give a sweeping seconds hand and a pusher feel closer to the real thing.
- Both types are easy to have serviced by a general watchmaker.
Cons
- Quartz versions tick, which is the fastest giveaway on the wrist.
- Mechanical copies can lose time, and a weak reset can leave the chronograph hand parked off zero.
- Push-pull crowns on some builds reduce water resistance to splash level only.
Use case: pick quartz for casual daily wear and mechanical if you want the sweeping hand and plan to handle the watch often.
Crystal, crown, and caseback
- Pros: sapphire crystal with anti-reflective coating, screw-down crown, engraved caseback with correctly spaced reference characters.
- Cons: mineral glass that scratches, shallow laser etching, and reference numbers printed with the wrong character count.
Use case: a sapphire crystal and screw-down crown are the two upgrades worth paying for, because both affect how the watch ages.
Red flags
- Seller claims the watch is genuine at a fraction of market price.
- Photos are reused from a catalog or another listing.
- No photo of the movement or caseback.
- Pressure to pay outside a protected method.
Compare reference details and photography conventions against the manufacturer's own product pages and a reputable secondary-market listing site before you commit, and treat any first copy as a replica in your own records.