Rolex Cosmograph Daytona 16523 Black Inverted 6 Dial Executed in Steel and 18k Yellow Gold, 1988

Dealer description — Bulang & Sons

Introduced in 1963, the Rolex Cosmograph Daytona was designed as a purpose-built chronograph for professional racing drivers, featuring its distinctive tachymeter bezel for measuring average speeds. Although initially a slow seller, it has since evolved into one of the most iconic and collectible wristwatches ever produced. For the first 25 years of its existence, every Daytona was manually wound. Recognising the need for a more modern chronograph, Rolex introduced the Reference 16520 in 1988—the brand's first self-winding Daytona. As Rolex had not yet developed its own automatic chronograph movement, it extensively reworked Zenith's legendary El Primero calibre, replacing roughly half of its components to meet Rolex's exacting standards. At the same time, the case diameter grew from 37 mm to 40 mm, the acrylic crystal made way for sapphire, and the dial received a more contemporary design with glossy lacquer and applied metal surrounds to the subdials. Presented here is the Reference 16523, the handsome Rolesor version combining stainless steel with 18 ct yellow gold. This particular example remains in excellent condition, with a strong case retaining thick lugs, well-defined crown guards, and a beautifully preserved "Units per Hour" bezel. The glossy black dial features the sought-after "inverted 6", where the numeral in the lower chronograph register is printed upside down—a small but desirable detail appreciated by Daytona collectors. The boat-shaped hour markers and matching hands have developed a warm beige patina, perfectly complementing the deep black dial and champagne-coloured subdials. The watch is fitted with its steel and yellow gold Oyster bracelet, reference 78363, complete with reference 403 end links and an M8-stamped clasp. The watch and its automatic movement have been fully serviced by our watchmaker and are ready to be enjoyed for many years to come. Early Zenith-powered Daytonas continue to attract a growing following among collectors, and the two-tone Reference 16523 remains one of the most wearable and characterful variants. For further information or to arrange a private viewing, please get in touch. Specifications: Rolex Daytona Reference 16523 Steel and 18k gold execution Serial r917xxx dating to 1988 Rare black “inverted six” dial Gold bezel,“units per hour” Rolex Osyter bracelet ref 78363 with 403 endlinks Calibre 4030 movement based on a Zenith movement Fully serviced by our watchmaker