*Avaliable at watchcentre.com
In 1972, Audemars Piguet decided to launch the world's first high-end sports watches in steel which they called the Royal Oak line. The Royal Oak set a trend that was followed by Patek Philippe in 1976 with its Nautilus line of watches and continues today with watches like Hublots Big Bang Chronograph.
Audemars Pigeut is sometimes mentioned as one of the top three Swiss Watchmakers in the world. While Patek Philippe and Vacheron Constantin, are widely acknowledge as holding the first two slots, the third slot is a point of contention between Audemars Pigeut, Blancpain, Breguet and Philippe Dufour.
Audemars Piguet Royal Oak Perpetual Calendar Model 25820SP.OO.0944SP.02. As is name indicates Audemars Piguet Royal Oak Perpetual Calendar is a perpetual calendar watch which displays the day, month and date in three subdials located at the 9-12-3 o'clock positions. The subdial at the 9 o'clock position also displays the leap-year indicator. The watch also features a moonpahse indicator at the 6 o'clock position.
The case of the watch has a case diameter of 39 mm, and the case and bracelet are made of a combination of platinum and stainless steel elements. The case is water resistant to 20 meters.
Perpetual Calendar. Many watches display the date on their dial. But since some months have only thirty, twenty-nine of twenty-eight days, you need to adjust the date at least five times per year. A perpetual calendar is a mechanism that automatically takes into account the varying number of days in each month as well as leap years so that the watch displays the correct date each month without the need of adjuctment. A perpetual calendar watch will not need correction for more then a century.
Movement. The watch is powered by the Audemars Piguet Calibre 2120/2802 movement, which is actually a modified Jaeger LeCoultre movement. This will be a dissapointment to many, since watches like Audemars Piguet Royal Oak Perpetual Calendar which have suggested retail selling price of nearly US$60,000 (and a maket price of just under US$48,000) usually have in-house movements. If it is of any comfort, Audemars Piguet owns 40% of Jaeger LeCoultre.
But this is an issue for such an expensive watch. Jaeger LeCoultre also releases its movement under it own brand name and the Jaeger LeCoulter Master Pertual Calendar watch list at just US$22,500, and can be purchased at a discount of 40% below list price.
The Calibre 2120/2802 is a self-winding movement which produces a unusual 19,800 vibrations per hour, rather the 28,800 vibrations per hour found in modern automatics or the 21,600 vibrations per hour found earlier models. The power reserve is 40 hours. I have not been able to find out why the Calibre 2120/2802 runs at this rather unusual speed. While the relatviely slow beat movement, it really does not matter much since the Audemars Piguet Royal Oak Perpetual Calendar does not have a small seconds hand.