Patek Philippe Nautilus 3712 x 5712

The Nautilus quickly rose to fame and remains one of the most talked-about watches in the world. Since the discontinuation of the 5711, its market value has skyrocketed to triple its retail price—creating the strange scenario where selling your “boring” Patek could yield you a year’s salary. But let’s set prices aside for a moment and forget the reference everyone seems obsessed with. Instead, let’s shine a light on a far more intriguing variation of this porthole-inspired masterpiece—the one with a power reserve, moonphase, decentral seconds, and date function.

In today’s watch guide, we’ll explore the 3712 and 5712—two seemingly similar Nautilus models with some critical differences.

I’ve been a watch enthusiast for nearly a decade, with a strong preference for classic and refined timepieces. I do enjoy sportier and tool-oriented pieces, but it took time for me to truly appreciate the Nautilus—not just as a design, but as a feat of technical watchmaking. When it finally clicked, I was hooked… on most versions, that is. The models with leather or rubber straps never did much for me. And for a while, neither did the 5712—I thought the dial was far too chaotic.

But everything changed the day I bought one. For the first time, I gave it the attention it deserved. I examined it in detail and realized how little coverage this reference had received. While the 5711 has been endlessly dissected in blogs and videos, the 5712 and its predecessor, the 3712, remain strangely underappreciated.

Maybe I’m the one to change that—not just by presenting the specs and history, but by sharing how my opinion shifted 180 degrees. Hopefully, I can spark the same fascination in you.

History

We’ll skip the oft-repeated tale of Gérald Genta sketching the Nautilus on a napkin in the 1970s. Fast-forward to the early 2000s: with the Nautilus approaching its 30th anniversary, collectors expected more than just new dial colors or case sizes. Until that point, Patek hadn’t significantly experimented with complications in the Nautilus line—except for the 3710, launched in 1998, which introduced a power reserve to the model for the first time.

Then in 2005, out of nowhere, Patek unveiled the 3712, combining a power reserve indicator, moonphase, decentral seconds, and a date—all packed into the Nautilus case. Just one year later, the 5712 debuted as part of the 30th Anniversary collection, but it was overshadowed by the chronograph reference 5980.

At first glance, the 3712 and 5712 seem nearly identical—but take a closer look and you’ll see they’re surprisingly different. Many collectors considered them odd or unbalanced, but if you give them time, you may just find that you (secretly) prefer them over the minimalist 5711 or even the original 3700.

Case

First of is the case. Slightly larger than the 5711 in order to house and display the complications. The 3712 and 5712 are only differing 1mm in case size and last mentioned is a tiny bit thicker, but more noticeable is that they do not share the same case construction at all! The 3712 is made with a Monobloc case, so out of 2 pieces; just like the first 3700 but with a crystal caseback. The 5712 uses a much more cost-efficient construction that we will see on all Nautilus from then on. The difference is not really visible without taking it apart, but look at the caseback where, unlike the 3712, the 5712 has a facet. 

From the frontside there’s also a difference in design that is easily and often overlooked. The hinges (or “ears”) used to be straight, but from 2006 onwards they were curved instead.

Crown

Over to the crown. They clearly have a different profile and the one from the 3712 is smaller, but what blew my mind is that the only the 5712 has a screw-down mechanism. Unlike popular believe this doesn’t necessarily affect the waterproofness. 

Bracelet & Clasp

Regarding the bracelet, I’m inclined to say they’re the same. Yet the profile of the centre-links is a tad rounder on the 3712. It’s hard to show but it reflects the light kind of different. The clasp is identical and uses a flip-lock and butterfly clasp.

Movement

For the movement both references count on the 240 PS IRM C LU. So the base caliber is the 240 that features 29 jewels, a straight-line lever escapement, shock absorber mechanism a self-compensating flat balance spring and a monometallic balance, adjusted to cold, heat, isochronism and 5 positions. 

To fully understand the letters, we need to already look at the dial. The “PS” stands for “Petite secondes” that is located at the right bottom of the dial. “IRM” is “Indication Reserve de Marche”, at the exact opposite side of the dial. “C LU” means “Calendrier et Lune” that we can find in the sub-dial at the 7 o’clock position.

The movement is powered by a micro-rotor in 22K yellow gold and hasn’t gone through many changes over the years. Prior to 2009 it was hallmarked with the Geneva Seal and afterwards we can find the PP seal.

Dial & hands

The most interesting feature is, without a shadow of a doubt, the dial. The classic gradient blue face with horizontal grooves is full of small differences between the 2 references. Let’s start top left; with the power reserve. Although the 3712 was only in production for a year, it is divided in 2 series. The first one has 3 red dots at the start and the later one, just like the 5712, has 4. So far this is common knowledge, but it is interesting to note and never published, the 5712 also comes in 2 series. From the first example in 2006 until 2008 it has one dot at the end of the Power Reserve, just like the 3712 has during its entire production run. But from 2008 onwards it features an extra dot next to the 48. 

The biggest difference can be found in the sub-dial underneath the Reserve de Marche. On the 3712 it is smaller and therefore giving room for a marker at the 7 o’clock position. Also, the baton at the 6 isn’t rounded of like it is at the 5712. To increase legibility, they used a bigger font for the date numerals on the 5712 and inverted the numbers from 9 to 23, along with thicker hour and minute hands.  

But here it is: why the 3712 is a better watch than the 5712. Not because the 3712 is way rarer and more historically important, or because the 5712 uses a cheaper case construction… But the finishing of the moon phase. Way more depth can be found in the 3712 where the stars are framed with thick lacquer unlike just a printed disc that we can find on the latter. 

Conclusion

For me, the 3712 is the more compelling watch—not because it’s rarer, or because it predates the 5712, or even due to its monobloc case. It’s about the details. The depth of the moonphase, the dial layout, the finishing—these elements slowly reveal themselves as you spend time with the watch.

Our opinions evolve with knowledge. Just like a child may not grasp the nuance of Chopin until they’ve matured, it took time and experience for me to appreciate the beauty of these asymmetric Nautilus references. And once I did, I couldn’t unsee it.

Comparing the 3712 and 5712 side by side has been a fascinating journey—and I hope you enjoyed coming along for the ride. Let me know your thoughts. Did I miss anything? Or better yet—did I convince you to see these watches in a new light?