The short answer
A fake IW371786 is a replica of the IWC Portugieser Chronograph, the round steel watch of roughly 41 mm with Arabic numerals, leaf-shaped hands, a 30-minute totalizer at 12 o'clock, and running seconds at 6. There is nothing exotic about that reference, which is exactly the problem. It is one of the most copied dress chronographs on the market, so two watches sold under the same number can differ by hundreds of dollars in parts and by years in how they age.
What separates the good copies from the bad ones is almost never the logo on the dial. It is the printing, the subdial spacing, the feel of the pushers, and what is ticking inside.
Why this reference attracts so many copies
Clean dials are easy to photograph and easy to sell. The Portugieser Chronograph has no date window, no tachymeter scale, no crown guards, and no bezel insert. Every detail sits on a flat surface you can photograph head-on. That makes it a favorite for replica makers, and it also means flaws are impossible to hide. A crooked marker on a busy dive watch can slip past a buyer. On this dial, a marker off by half a degree is the first thing you see.
Dial and hands: where copies give themselves away
The Portugieser dial is built on a fine railway-track minute ring, applied numerals, and thin feuille hands. I look at four things in order.
- Printing. Genuine dial text is crisp under a loupe, with even stroke weight. Cheap copies show fuzzy edges, letter spacing that drifts, and a logo that sits too high or too low.
- Subdial placement. The gap between the two counters should be symmetric and centered. Replicas often push one counter a millimeter off-center, and the eye catches it before the brain explains why.
- Numerals. Applied markers should sit flat with clean polished edges. On budget replicas they are glued slightly crooked or replaced with printed ones that lack any depth.
- Hands. Feuille hands taper to a point. Copies tend to be thicker, with rounded tips and dull polishing.
The crystal matters too. Newer Portugieser Chronographs use a box-shaped sapphire with anti-reflective coating on both faces, so the dial looks almost absent at an angle. Many replicas use flat sapphire with coating on one side only, and the glass reads as a grey film over the dial.
The movement question
The classic Portugieser Chronograph used a Valjoux 7750 base, reworked so the small seconds sit at 6 o'clock and the 12-hour counter is deleted. A stock 7750 puts running seconds at 9 o'clock, which is why so many replicas live or die on the movement. If the subdial at 9 is the one ticking, you are looking at an unmodified clone, and the dial layout will not match the reference it claims to be.
Better replicas use a modified 7750 clone or a Seagull chronograph movement with a transfer module. Top-tier copies can even show a decorated rotor through a sapphire back. Ask for a clear photo of the movement and a video of the chronograph starting, stopping, and resetting to zero.
Case, crown, and pushers
Proportions are where mid-tier replicas fall apart. The genuine case has a slim, softly polished bezel and lugs that curve down hard against the wrist. Copies often add half a millimeter of thickness, which makes the watch sit high and look bulky on a 6.5-inch wrist.
Press the pushers. They should have a short, firm travel with a clean click, not a mushy sponge feel. The crown should wind smoothly and pull to two positive positions. On many replicas the crown is signed but the teeth are cut too shallow, so it slips under your fingers.
Caseback and numbers
Newer versions of this reference have a sapphire caseback, so the movement is meant to be seen. A replica that arrives with a closed steel back on a reference that should be open is an instant tell. Engraved case numbers and reference codes should be sharp and consistent in depth. Laser-etched numbers look shallow and slightly grey.
What the price tiers actually buy
- Under $150: quartz or basic automatic, printed markers, hollow feel, wrong subdial layout.
- $200 to $400: Asia 7750 clone, decent dial, correct layout, soft pushers, average strap.
- $500 and up: decorated movement, sapphire on both sides, real alligator or good calf strap, correct case thickness.
A checklist before you pay
- Ask for a close-up of the dial at an angle, not straight on.
- Ask which subdial runs the seconds.
- Ask for the case thickness in millimeters.
- Ask for a video of the chronograph reset.
- Confirm the return policy and whether the strap is leather or synthetic.
What no replica gets fully right
Dial finishing and water resistance. IWC lacquers and sunbursts its dials to a level that replica factories rarely match, and the color shifts under different light on the genuine article. On water resistance, assume nothing. A replica rated at 30 meters is a splashing watch, not a swimming watch, and I would not shower in one. Gaskets are the first thing factories skip.
Legal and practical note
A replica is a copy, not a counterfeit, only as long as nobody sells it as the real thing. Passing one off as genuine is fraud in the United States and most of Europe, and watches bearing a protected trademark can be seized by customs. Buy it because you like the design, wear it honestly, and keep your expectations calibrated to what you paid.