Whereas the Royal Oak was born as a leisure/chic steel watch it wasn’t until the 25th anniversary of the model in 1997 that a chronograph complication was added to the catalogue, housing the automatic caliber Calibre 2385.Reference 25860 was in production until 2012.

As a commemoration of the first Swiss challenger to the America's Cup in Auckland, New Zealand, Audemars Piguet launched a limited edition Royal Oak City of Sails, Be Happy edition in 1999.The chronograph is limited to 300 pieces and is constructed of titanium, a sturdy but difficult to work with metal that is light and easy to wear. The dial has a clear and unique flair, displaying a deep blue tapisserie background, reminiscent of the blue oceanic tones and light blue skies. Furthermore, the dial also showcases yellow splashes of color for the hour, minutes and chrono hands reminiscing of those sunny summer days. The date aperture is interestingly placed between 4 and 5 o’clock. The rear of the case is inscribed with the phrase "City of Sails," a nickname for Auckland, New Zealand, which is recognized for its maritime heritage. The lightness and sturdiness of the case and bracelet enable the timepiece to deliver a comfortable and unique feel to the wrist.