Powering this Grand Complications piece is the self-winding mechanical Caliber R 27 HU, which delivers a minute repeater with two classic gongs for local time strike alongside a World Time function providing a 24-hour and day/night indication for all 24 time zones simultaneously. The 40.2mm white gold case measures 11.49mm in height and features hand-guilloché hobnail-patterned decoration on both the case and slide piece, complemented by skeletonized lugs. Two interchangeable case backs — one solid, one sapphire crystal — are included, and the case offers humidity and dust protection.
The dial is the defining artistic statement of the 5531G-001: a Grand Feu cloisonné enamel center portrays a steamboat on Lake Geneva in intricate hand-laid detail, set within an 18K gold dial plate and 24-hour ring. This centuries-old enameling technique demands exceptional skill, rendering each example a miniature work of art unique to the individual piece.
The watch is presented on a hand-stitched shiny blue-green alligator leather strap with square scales, secured by a fold-over clasp — a pairing that echoes the aquatic scene depicted on the dial and completes a watch that stands among the most technically and artistically ambitious references in the Patek Philippe catalog.
