The Short Answer
A fake Portofino 45 usually fails one test before any other: the power reserve. The watch people mean by "Portofino 45" is the IWC Portofino Hand-Wound Eight Days, a 45 mm hand-wound model built around the in-house 59210 caliber with a true eight-day reserve. Most counterfeits hide a generic automatic or hand-wound movement inside and stop in 36 to 48 hours. Wind it fully, set it down, and check it on day three. If it has died, the case is not authentic no matter how good the dial looks.
What the Portofino 45 Actually Is
The Portofino line spans several sizes, and only the largest one is the 45 mm hand-wound model, references in the IW5101 family. It has a polished case with a thin bezel, leaf-shaped hands, applied indices, a small seconds subdial, a date display, and a power reserve indicator on the dial face. The caseback is sapphire, which matters here: the movement was designed to be seen, so a counterfeit cannot hide the evidence.
Before You Start
- A 10x jeweler's loupe
- A phone with macro mode or a camera with a close-focus lens
- Digital calipers
- A timing app or a second watch for reference
- The correct reference number and published specs for the exact model you are checking
Step by Step
- Measure the case across the bezel at the 3 and 9 o'clock points, outside the crown, and write the number down. An authentic Portofino 45 reads 45 mm. Many fakes land between 42 and 44 mm because the builder reused a smaller case.
- Compare the measured thickness against the published figure for that reference. A counterfeit often runs thicker, since a generic movement and spacer sit taller than the IWC caliber.
- Wind the crown about 30 full turns, set the watch to the correct time, and start a timer. Put the watch crown up and leave it alone. The real 59210 should still be running after seven days.
- Examine the dial printing with the loupe. Authentic IWC text is crisp with sharp serifs, even spacing, and no blur at the edges. Counterfeit printing shows fuzzy borders and uneven letter height.
- Check the applied indices and the hands. On the real watch the indices sit flat against the dial with clean polished edges, and the leaf hands are evenly finished with a sharp center line.
- Study the date window. The genuine cutout is chamfered and the date font is thin and consistent with the rest of the dial. Fakes show a raw punched edge and a heavy, generic date wheel.
- Turn the watch over and read the caseback engraving. Reference and serial numbers are cut deep and clean, in a consistent font, on the real piece. Laser-etched or shallow stamped numbers are a strong sign of a copy.
- Look through the sapphire caseback at the movement. The authentic caliber shows Geneva stripes, blued screws, polished bevels, and an engraved bridge carrying the IWC name and the words Probus Scafusia.
- Weigh the watch in your hand and flex the strap. Real alligator or a proper leather strap has a firm, dense feel, and the buckle carries deep, even engraving.
- Take the watch to an IWC boutique or an authorized service center and ask them to confirm the reference against their records. This is the only check that closes the question.
Red Flags That Settle the Question
- A running time under three days after a full wind
- A solid steel caseback on a model that should have sapphire
- A movement with no engraving on the bridges
- Hands that are too short to reach the minute track
- A seller who refuses to open the caseback or meet at a service center
- A price far below the current secondary market range for that reference
What Buying a Replica Costs You
A counterfeit Portofino 45 carries no warranty, and IWC service centers will not touch it or supply parts for it. Independent watchmakers often decline the work as well, because the movement inside is an unbranded substitute with no parts support. Resale value is close to zero, and the watch carries a trademark that was never licensed. If your goal is the Portofino look at a lower cost, a used authentic reference from a reputable dealer is the path that keeps its value and can be serviced for decades.