Nautilus

The Nautilus began in 1976 as an unusual proposal from Patek Philippe: an expensive steel watch that could be worn beyond the circumstances of a gold dress watch. Gérald Genta gave it a broad, rounded eight-sided frame, a ribbed dial and a steel bracelet that continued the shape of the case. The original reference 3700 was wide but thin, with only two hands and a date.

Its resemblance to a ship's porthole was more than a drawing-room analogy. The original case opened from the front; the back and middle were one piece, and the frame holding the crystal was fastened down through the projecting sides. The shapes collectors call “ears” were part of that construction. A factory water-resistance rating of 120 metres made the purpose of the sealed case explicit.

The family gradually acquired smaller sizes, precious metals and additional functions. A major revision came in 2006. The 5711 retained the simple time-and-date face, adding a central seconds hand absent from the original 3700. Its case now had three parts and a transparent back, though the porthole outline remained. The 5712 offered a very different face inside a similar outline: a date indicated by a hand, moon phase, remaining running time and small seconds, distributed unevenly across the dial.

Those two watches show how much the Nautilus can change without losing its identity. The 5711 leaves the horizontal dial pattern largely uninterrupted. The 5712 cuts into it with overlapping displays. The broad frame and continuous bracelet make them recognisable as relatives before the reader has worked out what the extra hands do.