Judge any replica of reference IW371424 by the case profile first. Rest the watch on a flat surface and look at it from the side: the Portugieser Chronograph shape is a wide, thin case with a narrow bezel, a softly domed crystal and lugs that drop down steeply. If the midsection looks tall or the lugs sit flat and straight, stop there. Dial layout and printing come second, the movement third, and the strap last. Buyers who check in the reverse order end up with a watch that photographs well in a listing and wears wrong on the wrist.

What the Reference Number Tells You

The number sits in the 3714xx block, which points to the earlier generation of the IWC Portugieser Chronograph rather than the most recent revision. That generation is built around a two register chronograph dial: a 30 minute counter at 12 and running seconds at 6. Some versions carry a date aperture at 3, and the case back is usually a solid screw down engraved with the reference and a serial number.

Two layout details matter most. The watch is a chronograph, not a small seconds dress watch, so the hands at 6 should be running seconds for the time and the counter at 12 should advance when the chronograph runs. A dial where the 12 o'clock register is something other than a 30 minute counter belongs to a different reference and will read as a mismatch to anyone who knows the line.

Four Checks That Decide Quality

1. Case profile and proportions

Place the watch next to a photo of the original at the same distance. Compare the angle where the bezel meets the case band, the height of the mid case, and how far the lugs extend past the spring bars. A thinner case with a domed crystal is the goal. A thick slab sided case with a flat crystal is the most common giveaway, because it is cheaper to machine and hides a deeper movement.

2. Dial layout and printing

Check the spacing between the two registers: on the original they sit close to the centre, leaving a wide margin of dial before the chapter ring. Then check the printing itself. The brand wordmark and the subsidiary text should be crisp at arm's length, with even letter spacing and no bleeding into the dial finish. Applied numerals and indices should catch light on their edges, not lie flat like paint.

3. Movement and pusher feel

A chronograph should start, stop and reset with a firm, short click. Mushy pushers or a reset that hesitates suggest a cheap module stacked on top of a base movement. Ask what beats inside: a four hertz automatic chronograph with the correct 12 and 6 register layout is the target. A stock three register layout with running seconds at 9 o'clock is wrong for this reference and is easy to spot in a straight on photo.

4. Strap, clasp and case back

Look at the leather grain and the stitching line, then look at the buckle or deployant. On a decent build the strap tapers evenly and the hardware is polished on the visible face and brushed elsewhere. The case back engraving should be deep and evenly struck. Shallow laser etching that fades under a fingernail is a sign of a rushed case.

Parameter Bands Worth Measuring

  • Case diameter: roughly 40.5 to 41 mm. Anything at 42 mm or above stretches the subdial spacing and wears larger than the reference.
  • Case thickness: about 12.3 to 13.5 mm including the crystal. Under 11 mm usually means a slim module or a quartz movement.
  • Lug width: 20 mm, which limits how many aftermarket straps will sit flush against the case.
  • Water resistance: rated at 3 bar on the original, so treat it as splash protection and nothing more.
  • Beat rate: four hertz, which gives a smooth sweep on the running seconds at 6.

Pitfalls That Show Up in Listings

  • Photos taken only from the front, which hide case thickness and lug angle.
  • Seller text that describes the movement only as high quality automatic, with no mention of the register layout.
  • Subdial hands that are too long, crossing into the numerals on the counter at 12.
  • A date aperture cut off centre, with the numerals sitting low in the window.
  • Crystal with a heavy blue tint from a cheap anti reflective coating instead of a colourless one.
  • Case backs shown at an angle so the engraving cannot be read.

FAQ

Is IW371424 still in production?

The reference belongs to an earlier generation of the Portugieser Chronograph, and the line has been revised since. Compare any modern listing against the current reference data before you assume the specs match.

What movement should a good replica use?

An automatic chronograph running at four hertz with the correct 12 and 6 register layout. The pusher feel and the instant snap back to zero on reset tell you more than a calibre name in a listing.

How do I check proportions without calipers?

Photograph the watch beside a coin or a ruler at the same focal length, then compare the silhouette with a reference image. Lug angle and case height show up in a side profile shot.

Does the strap matter?

It matters more than most buyers expect, because the strap sets the visual width of the watch on the wrist. A stiff, glossy strap makes a well finished case look cheap.