Early technological advances

During First World War, the British government levied a heavy import duty, and this decision forced Wilsdorf to transfer the export of his watches to his office in Bienne, which he had opened in 1912. In 1926 the Rolex Oyster was released.Wilsdorf reportedly came up with the name at a dinner party when he had a hard time opening an oyster. He apparently said to other guests that he hoped his new watch would prove to be as resilient as the oyster.
True to his word, the Oyster was indeed sturdy. It was the first wristwatch to be considered waterproof.which was proven the following year when a British woman, Mercedes Gleitze, wore it in her successful bid to cross the English Channel. She emerged from her fifteen-hour swim with the watch functioning perfectly. This was great publicity for Wilsdorf, who had sponsored the event and gained considerable worldwide exposure for his new Oyster Watch . The timepieces were displayed prominently in jewelers' shop windows, inside a fish tank totally submersed in water;
Wilsdorf's next triumph came in 1931 when the Perpetual Rotor was created, (Rolex DateJust watches)a mechanism that was the basis for self-winding movements. So Wilsdorf had invented not only the first truly waterproof wristwatch but also one that relied on just the simple movement of the wrist to power itself.















