The Aquanaut was released in 1997, as the first to be fitted with a rubber (ortropicalas it was known) strap. Initially limited to just 1,000 pieces (as the ref. 5060A and 5060J), themodelwasintroduced shortly after the brands first highly-successful sportswatch, the , celebrated its 20th anniversary.

This example - the ref. 5066Awith blue dial - was launched in 1998, shortly after the initial references, and produced exclusively for the Japanese market. It is believed that approximately 500 examples were made, with very few coming to market.

The Aquanaut re-interprets a number of signature design elements from the Nautilus - most notably, the octagonal rounded bezel. It displays a high level of finishing, with brushed surfaces on the case front, and polished, bevelled edges. The steel, three-piece case provides water resistance up to 120m, further featuring a screw-down crown.

The blue checkerboard dial contrasts beautifully with the polished, steel bracelet, and is embossed with silver, applied Arabic numerals. The luminous material is tritium, and has aged to a subtle creamy tone.

The movement inside the reference 5066A is the self-winding calibre 330 SC. It features 29 jewels, a straight-line lever escapement, shock absorber mechanism a self-compensating flat balance spring and a monometallic balance, adjusted to cold, heat, isochronism and 5 positions. Furthermore, the solid-gold rotor is finished in classic Patek Philippe style, with circular Geneva stripes.

The watch comes with itsCertificate of Origin, which dates to April 1999 (based on the PKSS code referenced at the bottom of it) and its original leather pouch. It is also accompanied by a Patek Philippe service receipt from November 1999 and a strap sizing manual.This Patek Philippe 5066A comes fitted with the brand's steel bracelet.

Viewings can be arranged in Central London by appointment.

Closer look