The designer of the Nautilus, Gerald Genta have told that he designed the watch that was later named Nautilus during the Basel Trade Fair:
-"I was at the restaurant of a hotel and some people from Patek were sitting in one corner of the dining hall, while I was sitting alone in the other corner. I told the head-waiter: “Bring me a piece of paper and a pencil, I want to design something” and I designed the Nautilus while observing the people from Patek eating! It was a sketch that I completed in 5 minutes".
The inspiring idea was the shape of a porthole, like those that could be found on transatlantic liners. The patented case was formed by a solid backcase/middlecase monobloc and the distinctive octagonal bezel secured to it by four lateral screws to ensure water-resistance. Each of the eight sides of the bezel were subtly curved to trace a perfect arc of a circle, a subtle detail making a big difference from a design point of view.