Cartier offered watches with water-resistant cases in the 1930s, but their insulating systems were so involved that the protection they offered lasted only a relatively short time. Although Louis Cartier died in 1942, his brand continued to strive for technical innovation and design evolution. Recognizing that it was easier to secure and sustain water-resistance in a round case, Cartier launched a round, gold model in 1943.
The crown had a protective locking mechanism that could be screwed shut after the owner had used the crown to wind the watch or set its hands. To prevent the loss of this protective cap, a small chain kept it safely attached to the case. The crystal was covered with a grille that resembled those on military wristwatches from the World War I era. Incidentally, the claim that this watch was created to fill an order placed by the Pasha of Marrakesh is nothing more than a rumor. Not until 1985, when Cartier began serial manufacturing of this model, was it given this name, though the Pasha was among Cartier’s foremost enthusiast in his day.