By 1926, Rolex had invented the world’s first waterproof wristwatch, the Oyster, and in 1931, the first wristwatch self-winding system with a free rotor, called the Perpetual. These patented innovations and landmarks in watchmaking formed the foundation for today’s Oyster Perpetual Yacht-Master and Yacht-Master II. Rolex used the world as a real-life proving ground for the Oyster, demonstrating, time and again, its reliability in the most extreme conditions — be it at sea, in the depths of the ocean, on land, in the air or at the tallest peaks. By being associated with so many achievements, Rolex watches established themselves as a trusted reference. Waterproof, robust and accurate, Rolex Oyster Perpetual chronometers are uniquely suited to life at the helm.