Short answer
A replica Portofino Small Seconds 37 is a counterfeit copy of the IWC Portofino Automatic 37, a 37 mm dress watch with a small seconds subdial at 6 o'clock. IWC is the only maker of that watch. Every unit sold as a replica is an unlicensed copy, and importing, selling, or passing one off as genuine carries legal and financial risk. The skill worth having is telling the two apart.
What the genuine watch is
- Case: 37 mm across, about 9 mm thick, in polished stainless steel or 18k gold, with a smooth bezel and slim lugs.
- Dial: hours and minutes from the center, small seconds in a subdial at 6 o'clock. No date. No chronograph.
- Hands: leaf shaped hour and minute hands, plus a small subdial hand.
- Crystal: sapphire with anti reflective coating on both faces.
- Back: solid, engraved with the reference number, the serial number, and the IWC name.
Prerequisites
- Digital calipers or a ruler marked in millimeters.
- A 10x loupe or a phone camera with macro mode.
- A kitchen scale accurate to 1 gram.
- Photos of the genuine reference from the manufacturer catalog for side by side comparison.
How to check a watch step by step
- Measure the case across the bezel without the crown. The genuine measurement is 37.0 mm, and most copies land between 38 mm and 40 mm.
- Measure the thickness from caseback to crystal. Copies run thick because the case has to hold a stock movement.
- Weigh the watch on the scale. A genuine steel piece sits near the published figure, while copies drift light or heavy.
- Look at the subdial at 6 o'clock under the loupe. On the genuine dial it is centered on the vertical axis and spaced evenly from the center hands. On copies it shifts off axis.
- Study the printed text. Genuine printing has sharp edges and even stroke weight. Copies show fuzzy or doubled lettering.
- Check the hands. Genuine leaf hands are polished on the bevel and flat on top, with no burrs at the tips.
- Tip the crystal toward a light. Genuine sapphire throws a faint blue or purple reflection from the coating. Mineral glass on a copy shows a dull white glare.
- Read the caseback engraving under the loupe. Genuine engraving has crisp, deep cuts. Laser etching on copies looks shallow and gray.
- Compare the reference number on the caseback against the catalog. A number that does not exist for that dial and case combination is the clearest sign of a copy.
- Turn the crown slowly and feel the resistance. A rough or gritty wind points to a low grade movement.
- Have an authorized watchmaker open the case and identify the movement. This is the only check that settles the question.
Why the difference matters
Counterfeit watches are seized and destroyed at the border in the United States, and trafficking in them is a federal offense. A copy also carries no warranty, no service path, and no resale value, and it will not hold up to water exposure the way the genuine case does. If you already own one, do not list it for sale as a genuine watch, and have a watchmaker confirm what is inside before you spend money on service.
Where buyers get caught
- Trusting a listing photo that shows a genuine watch but ships a copy.
- Accepting a box and papers as proof. Those items are copied too.
- Assuming a low price is a bargain. It is the warning sign.