Home » IWC Watches » IWC Portuguese Sidérale Scafusia Watch
This summer, IWC from Schaffhausen introduced their most exclusive and most complicated mechanical timepiece ever, the Portuguese Sidérale Scafusia. It is the first IWC watch that features a patented constant-force tourbillon together with many other complications and individually calculated astronomical displays. Special exclusivity is that every Portuguese Sidérale Scafusia timepiece will be made on a special request and it will be unmistakably unique.
According to the Swiss manufacturer, after ten years of intensive research, the company has succeeded in uniting solar time with sidereal time, together with astronomical displays, in a single watch. This technological masterpiece of Haute Horlogerie comes with the wealth of numerous surprising complications and new advanced technical features.
As the IWC CEO Georges Kern has recently said for a Swiss newspaper Le Matin, the real purpose of the watch is to attract people to the brand and to show the company’s technical capabilities. Also, he said that IWC is aware that it is not a commercial project and that they will be happy to sell ten pieces a year. However, the true horological masterpiece from IWC will leave speechless all watch connoisseurs worldwide.
A Unique Masterpiece from IWC
Portuguese Sidérale Scafusia, unlike most mechanical watches, has displays on both sides. The design of its dial has the same characteristic style as the entire IWC Portuguese watch family. The contemporary dial on its central part features the globe of the world with engraved lines of latitudes and longitudes. Considering the fact that there are two types of days that differ in length, a solar and a sidereal time, IWC provided the readings of both. The solar time is based on the length of the average day that lasts precisely 24 hours and measures the average time between the passages of the sun over a given meridian. On the other hand, a sidereal time measures the time taken for the earth to complete the rotation around its own axis. Considering the fact that the earth also describes an arc around the sun, a sidereal day is approximately four minutes shorter than the solar one. Therefore, on the dial side of Portuguese Sidérale Scafusia Watch at the 12 o’clock position there is a 24-hour counter that shows sidereal time with outstanding precision (it is accurate to +/- 11.5 seconds per year).

IWC Portuguese Sidérale Scafusia Watch IW5041
The solar time (or the current time of a day) is displayed by traditional central hour and minute hands, whereas the seconds are shown on a 60-second constant force tourbillon at the 9 o’clock position. A large-sized open tourbillon on the clean and refined dial makes for a visually thrilling experience. It is quite impressive for its sheer size (it takes almost a quarter of the entire bottom plate), and if we add to this the unusual design – the pleasure becomes even greater. In the lower right quadrant of the dial, between 4 and 5 o’clock positions, there is a 96-hour power reserve indicator.
A Celestial Chart
On the case back, things get much more complex where a number of astronomical functions are displayed. The most striking feature on the back of the watch is the beautifully designed celestial chart showing the stars in the night sky as seen from a specific point on the Earth’s surface. The large astrological chart is based on a specific sky location the customer must choose. The night sky disc changes throughout the day (from twilight across sunrise to sunset – visit www.iwc.com to see how it works).

IWC Portuguese Sidérale Scafusia Watch IW5041 Caseback
As the manufacturer claims, the chart can display the actual position of about 500 to 1,000 stars. The sky disc can rotate in both directions – clockwise or anticlockwise, depending on whether the selected geographic location is in the northern or southern hemisphere. A spectacular celestial chart includes several astronomical functions, such as a customized celestial chart and horizon, sidereal time and solar time, day, night and dusk display under the celestial chart, a sunrise and sunset display, as well as a perpetual calendar with a display showing leap years and a number of days (from 1 to 365 or 366). The watch of this level of complexity indeed demands hours of careful exploration!!!
An Impressive Tourbillon
After all this, I have no doubt that the caliber 94900 that powers this mechanical masterpiece is extremely impressive on all accords. The hand-wound movement has over 500 pieces. Built on amazing 56 jewels, the movement runs at 18,000 beats per hour and has a new balance with two adjustment cams and two adjustment weights, Breguet hairspring, double power barrels and a constant power tourbillon. Although the movement allows 4 days of power reserve, the middle 48 hours offers totally consistent power and perfect accuracy to the movement.

The front view of the movement

The back view of the movement
Over 200 Different Design Options
As I previously mentioned, the Portuguese Sidérale Scafusia watch will be made on a special request with countless different combinations. You can choose among precious metals, such as platinum, 18-karat white gold or 18-karat red gold for the case, five different colors for the dial, various colors for the appliqués and straps, as well as the material used for the straps (the choice is between the finest alligator leather and equus-hide straps, both ending in IWC folding clasp). Thus, there are over 200 possible combinations.
Each timepiece is crafted to resist the rigors of every day use, even though it will most likely end up in collectors’ winder equipped safes. Every Sidérale Scafusia watch is protected by a convex sapphire glass with double antireflective coatings on both sides and provides water-resistance up to 30 meters (100 feet). Its round case measures 46 millimeters in diameter, with the thickness of 17.5 millimeters.
This stunning piece of haute horology with the referent number 5041 will be personally presented to its new owner in a top-quality watch case which includes a removable casket, covered in alligator leather, and an automatic winder, especially developed for this watch. The winder winds the watch autonomously once a day via the crown.

IWC Portuguese Sidérale Scafusia Watch Box
The IWC Portuguese Sidérale Scafusia has been created undeniably for collectors and lovers of fine timepieces. If you want to buy this IWC’s masterpiece, you will have to pay approximately $820,000. Also, you will have to wait for about one year for delivery, so you better put in your order soon.