Patek Philippe introduced reference 3712/1A in 2005, and it remained in production for approximately one year – some estimate as few as eight months. Originally designed by world renowned Gerald Genta, the first Nautilus reference 3700 was presented in 1976 and has remained a staple within the Patek Philippe collection.

At the time of launch reference 3712/1A was the most complicated Nautilus ever produced by Patek Philippe. The letters following the official name of the self-winding caliber 240 – PS IRM C LU – stand for ‘petite second’ (small seconds), ‘indication de réserve de marche’ (power reserve), ‘calendrier’ (date), and ‘lune’ (moon), all of which are present on the 3712 in an idiosyncratic but somehow harmonious arrangement.

The reference 3712 is similar to its successor, the reference 5712 but a cavalcade of details make the two quite different. The reference 3712 has a two case construction with sharp lugs and measures 42mm whereas the reference 5712 has a three piece case construction with rounded lugs and measures 43mm. Other differences can be found on the dial with the reference 3712 having wider grooves and different markers than that of its sibling. The center links of the bracelets are equally different.

During its production cycle, the reference 3712 was offered with a power reserve indicator with three red dots or four red dots, like in the present model, indicating a low reserve. This may seem like a small detail but it presents great interest to collectors and scholars.

It is incredible that Patek Philippe produced this reference for only one year, consequently making the reference 3712 one of the rarest versions of the Nautilus, 40 of which have appeared on the market in the past decade.