The Short Answer

Judge a replica IW371765 by the case profile and the subdials, not by the listing photos. The Portugieser Chronograph is a thin, wide, flat-sided watch with a vertical two-register dial, and those two traits are exactly what replica factories get wrong first. Before you send money, ask the seller for three things: caliper photos of diameter and thickness at the caseback edge, a straight-on dial shot in daylight at 12 o'clock, and a short video showing the chronograph start, stop, and reset with the running seconds hand sweeping. If those cannot be produced, the watch is not worth the risk regardless of the tier name attached to it.

Start With the Genuine Reference

The IW3717xx suffix places this watch in the Portugieser Chronograph 3716 generation, a family that shares a 41 mm case, roughly 13 mm of thickness, a vertical bi-compax dial (running seconds at 6, chronograph minutes at 12), leaf-shaped hands, applied Arabic numerals, and IWC's in-house 69355 chronograph caliber. Dial color, strap material, and case metal change with the suffix, so pull the official spec sheet for your exact variant before you compare anything. A replica is only accurate against a specific reference, not against the line as a whole.

What to Look For

Case and Thickness

Measure it. Genuine 3716 cases sit near 13 mm thick, while many replica builds based on a modified 7750 architecture run 14.5 to 15 mm. That extra millimeter changes how the watch sits under a cuff and is the single clearest tell in person. Also check the lug curve, the thin polished bezel band, and the crispness of the caseback engraving, which on cheap builds looks stamped rather than cut.

Dial, Printing, and Numerals

Look for applied numerals with polished bevels and sharp inner corners, a clean minute track, and subdials with visible concentric snailing rather than flat discs. Printing should be thin and even. Thick, raised, or fuzzy lettering signals a low-grade dial. If the variant you want has no date window, a replica that adds one is a different reference entirely.

Hands and Subdials

The leaf hands should be beveled, correctly proportioned, and long enough to reach the minute track. Confirm which register does what. On the genuine layout, the chronograph minutes sit at 12 and the running seconds at 6. Replicas with a dead subdial, a 24-hour indicator at 12, or a seconds hand that ticks instead of sweeping are cosmetic shells.

Movement Behavior

Ask for a video with sound. Pusher feel should be firm with a clean click, the chronograph should reset to zero in one snap, and the sweep should be smooth. Request a movement photo where possible and check that the rotor and bridges are finished rather than raw. Note that the genuine caliber carries a column wheel and roughly 46 hours of reserve, so a replica claiming identical internals at a bargain tier is overstating itself.

Strap, Caseback, and Sealing

Alligator-grain straps should have a soft hand and even stitching at the lugs. Caseback text should match the reference you are buying. Treat water resistance as unverified on any replica and keep it away from water until a watchmaker pressure-tests it.

Quality Tiers and What Each One Buys

• Entry tier: correct overall silhouette but thicker case, flat subdial discs, and a basic chronograph movement. Fine for photos, weak in hand.
• Mid tier: closer case thickness, snailed registers, better printing, and a properly functioning chronograph. This is where most buyers should shop.
• Top tier: clone-style movement with decorated bridges, measured thickness within a fraction of a millimeter, sharp applied indices, and correct engraving. Ask for QC photos of your exact unit, not stock images.

Common Pitfalls

• Stock photos of the genuine watch used as product images.
• Listings that never state case thickness.
• Dead or decorative subdials on otherwise convincing dials.
• Caseback reference text that does not match the dial variant.
• Sellers who refuse a live video or third-party QC pictures.
• Payment by irreversible methods with no inspection window.

FAQ

How can I tell the tier from photos alone?

Start with the side profile and the subdials. A thin case edge and properly recessed, snailed registers indicate a better build. Flat, printed subdials with a thick case point to entry tier.

Does the running seconds hand position matter?

Yes. On the genuine layout the small seconds sits at 6 and the chronograph minutes at 12. A replica that reverses this or uses a 24-hour hand at 12 is not faithful.

Should I expect sapphire crystal?

Most mid and top tier replicas use sapphire with an anti-reflective coating. If a seller cannot confirm the crystal material, assume mineral glass.

Is a thicker case always a red flag?

Not always, but it is the most consistent indicator of a cheaper movement architecture. Measure before you commit.