IWC Portuguese Sidérale Scafusia

About this reference

The IWC Portugieser Sidérale Scafusia reference IW504101 was introduced in 2011 as a built-to-order flagship and remains the most complex timepiece in the brand's history. Production is extremely limited due to the bespoke nature of each piece, which requires approximately one year to manufacture. The watch features the manual-wind caliber 94900, incorporating a constant-force tourbillon, a 96-hour power reserve, and a unique celestial display on the caseback customized to the owner’s specific geographical coordinates. The 46mm platinum case houses a dial displaying both solar time and sidereal time. Collectors value this reference for its astronomical complications, including a perpetual calendar and sunrise/sunset indications. On the secondary market, these timepieces typically command prices in the mid-to-high six-figure range, often between $350,000 and $500,000. A notable aspect of production is that no two examples are identical because the star charts are calibrated to individual locations.