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 was presented in 1976. The reference 3712/1A with power reserve, date, and moonphase, was at the time of its launch the most complicated version of the Nautilus made 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), "calandrier" (date), and "lune" (moon), all of which are present on the 3712 in an idiosyncratic but somehow harmonious arrangement.

At first glance, the 3712 appears quite similar to its successor, the 5712, but there are many noteworthy differences when the details are examined. Most notably, the 3712 has a slightly smaller case measuring 42mm in diameter as it is constructed using only two pieces compared with the more rounded, tripartite 43mm case of the 5712. The dial of the reference 3712 features wider grooves, or channels, and different hour markers than its successor. A particularly subtle but well-studied detail is the presence of just three red dots on the power reserve indicator, versus four dots on the 5712, to indicate a low remaining power reserve.

With its extremely short production period, the reference 3712 is amongst the rarest of all variants of the Nautilus, making it extremely sought after. Still single factory sealed and as such preserved in untouched condition, this watch is sure to please all Patek Philippe collectors.