Short answer
A replica Portofino Small Seconds 37 copies a 37 mm IWC dress watch with a subdial at 6 o'clock. Street prices in the US run from about $150 to $450. The case width and the subdial hand carry most of the look. The movement carries the rest. A $150 copy with a true 37.0 mm case reads better on the wrist than a 40 mm copy with a polished rotor.
The original it copies
IWC sells the Portofino Automatic 37 as its small dress model, below the 40 mm Portofino. IWC lists a 37 mm case and 30 m water resistance for that line. Thickness figures change between sources, from about 9 mm to 9.4 mm. Published figures put the automatic calibre near 42 hours of power reserve. Confirm the calibre and the reserve for the exact reference you want, since dial variants differ.
Details that matter on the original: thin bezel, short lugs that curve down, sapphire crystal, signed crown, alligator strap. Dials come with Roman numerals or applied batons depending on the reference.
Where replicas differ
Most flaws sit in four places: case size, dial print, subdial geometry, and the strap.
- Case: measure across 3 to 9. Good copies land at 37.0 mm to 37.2 mm. Copies built on a 40 mm blank fail this test.
- Lug width: 18 mm on most 37 mm Portofino references. A 20 mm strap will not fit.
- Subdial: ring printed at 6 o'clock, not a deep stamped groove. The small hand should reach the printed track. Short hands sit inside the track and read as wrong.
- Print: "IWC SCHAFFHAUSEN" and "PORTOFINO" as separate lines, even letter spacing, no blur at 10x zoom.
- Crystal: sapphire on good builds. Mineral glass shows a purple tint at an angle.
- Caseback: solid on most 37 mm references. A clear caseback on a replica is a tell unless the reference has one.
- Crown: small, signed, correct gap to the case.
Movement choices
A small seconds hand needs a movement with an offset seconds train. A plain 2813 cannot drive a subdial without a module. Common choices in this band are Seagull ST17 and ST21, plus 2824 clones fitted with a subdial module. Ask for the calibre name. Ask for a movement photo. A rotor engraved with a brand name over a generic automatic is a costume part, not a calibre.
Beat rate covers part of the story. 21,600 vph gives 6 ticks per second on the small hand. 28,800 vph gives 8. Both appear in replicas. Neither proves quality alone.
Inspection list before you pay
- Ask for caliper photos: case width at 3 to 9, lug to lug, and lug width.
- Ask for a video of the small seconds hand running. Look for stutter and for the hand stopping at the same point each minute.
- Ask for a macro photo of the subdial. Check hand length against the printed track.
- Ask for a photo of the crown and the caseback engraving.
- Ask which calibre is inside and who regulated it.
- Pay with a method that allows a chargeback. Skip sellers who take bank transfer only.
Price bands
$120 to $180 buys mineral glass, stamped dial print, and a basic automatic. $200 to $300 buys sapphire, better print, and a Seagull automatic. $350 to $450 buys the closest copies: correct case, decent strap, regulated movement. Above $500 you pay for packaging, not parts. These are broad bands reported by buyers. Prices move with sellers.
Limits and legal note
No replica in this band is built for water. The 30 m rating on the dial means splashes, not swimming. Gaskets in copies are thin and dry out with age. Service is hard: many watchmakers refuse replica work, and a $100 service on a $200 watch does not pay. Resale is close to zero.
Trademark note: importing or selling counterfeit goods is illegal in the US. Customs can seize a shipment. Check your local rules before you order.