4160 MOVEMENT
The heart of the movement beats at 28,800 vibrations per hour. Its blue PARACHROM hairspring with a Breguet overcoil is up to 10 times more resistant to shocks and insensitive to magnetic fields. This Rolex innovation endows the watch with excellent chronometric performance certified by COSC (Contrôle officiel suisse des Chronomètres - Swiss Official Chronometer Testing Institute).
The countdown mechanism is constructed using a column wheel and a vertical clutch. The choice of this exclusive architecture is clearly characteristic of the Rolex new-generation chronograph movements.
Rolex engineers and watchmakers achieved an impressive technical feat by developing a new mechanical programmable countdown function. A mechanical memory system makes it possible for the wearer to program, in advance and permanently (unless it is intentionally modified) the countdown time for the start of a regatta. The watch can be used in regattas with various starting sequences.
Fully automatic, equipped with a Perpetual rotor, the Yacht-Master II movement has a power reserve of 72 hours.
