Patek Philippe Nautilus was designed to represent the port hole of a ship. It is Patek's stainless steel diving watch allowing water resistance up to 120m. At 40mm it is similar size to the Rolex Submariner however it features the mechanical self-winding 324 S C movement with date function. The nautilus resonates at 28800 and has a 35-45h power reserve. It also features the Patek Philippe seal which can be seen from the sapphire reverse. The nautilus is available in a chronograph but the most popular is the chronometer 5711 1a-010.