The Evolution of the Super Compressor
Perhaps one of the most misused and misunderstood terms in the watch community is the term “Super Compressor”. These days, the term tends to be used interchangeably with a dual-crown dive watch - but this wasn’t always the case. As a matter of fact, there were plenty of cases that used Super Compressor technology - which at the time was considered advanced - but utilized only one crown. The history is rather murky, but there are some great articles around the web that give an in-depth look at what an authentic Super Compressor is and the benefits of using one. In this post, I’ll give a quick rundown of what it all means and how our latest release, the Duality, can trace its lineage back to the original Super Compressor. For the sake of relevance, we will use “SC” to refer to dual-crown Super Compressors.
The whole concept of the SC was to increase in water resistance as the watch went deeper underwater, through the use of a system that consists of a spring-loaded caseback and a rubber gasket. While many dual-crown dive watches claim to be “super compressors,” the truth is that unless it was manufactured by one specific company, EPSA, it is not an authentic SC, though attempts have been made to recreate modern interpretations of the construction.
In the mid-to-late 50s, Swiss case manufacturer Ervin Piquerez S.A. (EPSA) filed patents and began manufacturing their latest and greatest catalog component, the Super Compressor case, for brands such as JLC, Longines, and Blancpain. There are a series of patents easily found online that show the evolution that led to the construction of a SC case. You can view them here and here.
Before the 70s, it was extremely common for brands to use catalog components from general case manufactures such as EPSA and Squale - something that contemporary counterparts rarely, if ever do. As a result, many of the vintage SCs that have survived through the years share common and identifiable components, even between competing brands. Nowadays, modern brands have little to no choice but to assume the entire risk and cost of a full production run of custom non-catalog cases.
With the Duality, we paid our respects to SC ancestry, but rather than include many of the distinct indicators of an authentic SC, we attempted to push beyond that and ultimately pave a unique and innovative path for the future of dual-crown divers. In order to do so, we needed to understand what differentiates an authentic EPSA SC from any other dual-crown watch.
Super Compressor Technology
The defining feature of the SC case was the spring-loaded mechanism in the caseback, which applied more pressure against the O-ring gasket as the external pressure of the water increased, thus creating a tighter and fuller seal. There were a few benefits for using this system. At the time, manufacturing capabilities were not nearly as advanced as they currently are, so achieving anything beyond 50 meters of water resistance posed a serious challenge.*
Perhaps the most functional benefit of this patented technology was the increased longevity of the rubber o-ring gaskets. Although vulcanized rubber had been developed 100+ years prior, the less-than-adequate manufacturing tolerances required that in order to achieve water resistance, the caseback had to be so securely tightened that the lifespan of the rubber gasket was cut to essentially one or two dives.
By utilizing the new SC system, gaskets were not under full tension unless the watch was under pressure, therefore prolonging the life of the gasket. And let’s face it: how often do you get your gaskets checked? Do you think that they did it any more often back then?
With modern manufacturing capabilities, the original Super Compressor system has been rendered unnecessary at best - but it is important to recognize the benefits of this design and see where else this benefit might be necessary.
Another distinct indicator of a genuine EPSA SC case was the crown(s), which were typically not screw-down crowns. After operating an authentic SC, it becomes obvious why it was constructed this way - screwing down the crown would lead to unwanted rotation of the internal bezel, making the bezel difficult to set accurately for dive-timing. However, such a construction would require a gasket under constant pressure leading to friction upon turning the crown, which would dramatically reduce its lifespan.
In order to get the best of both worlds - bezel functionality and gasket longevity - the Duality’s crowns utilize a decoupling mechanism. The mechanism allows the crown to disengage when being tightened, thus preventing the bezel from rotating and the movement from winding. In a similar fashion to the original SC, tension is only applied to the gaskets when they are in use - and wear-and-tear caused by friction is reduced dramatically.
On genuine SC cases, EPSA typically engraved a crosshatch pattern, over which some brands elected to engrave their own logo.** It was EPSA’s way of defending their authenticity, as other manufacturers began to create their own versions of dual-crown cases, many of which did not utilize the original SC caseback mechanism.
As a throwback to this defining feature of the SC, we used a similar crosshatch pattern that we’ve grown very fond of, both from a functional and aesthetic standpoint, and have used in past models (i.e. Contrail and Avalon).
Instead of a crosshatch pattern on the ends of the crowns, we chose to apply sapphire glass inlay that features our “knot" logo on the four o’clock crown and the "Duality” emblem on the two o’clock crown - both are printed with lume for low-light functionality.
Another indicator of an authentic SC was the caseback design, which had what would now be considered an antique diving helmet stamped into it. The catch is that this was usually done on the inside of the caseback, but many brands replicated it on the outside for decoration. While this was purely an aesthetic feature that had no utility, it was an important part of the watch, as it separated the copycats from the real deal.
The Duality is not a SC, therefore it does not have an antiquated diving helmet graphic anywhere on the caseback. The caseback does, however, feature a stamped “Duality” emblem, symbolic of the concept behind the watch, represented by contrasting finishing between rough bead-blasting and high-polish (the two o’clock crown also features the emblem).
Dial, Hands, and Bezel
One of the few areas where brands could leave their own mark on their SC watch was with the dial, hands, and bezel. When it came to the Duality’s dial and hands, it was important for us to infuse Nodus DNA into it. You might recognize the indices and hands from the Contrail, a fan-favorite from 2018, as we began development of the Duality around the same time as the Contrail.
The Duality’s dial is an interesting one - it features a two-layer sandwich construction with applied indices on the top layer - something we are calling the hybrid dial. The benefit of the hybrid dial is that we can pack it full of lume for visibility in dark environments, keep the shimmer of applied indices for daytime visibility and ornamentation, and most importantly, create a stunning-looking dial full of depth and dimension.
There isn't too much to be said about the mid-case of a SC - they were all pretty straight forward: mix of brushed and polished surfaces and capable of handling bumps and bruises. The design aged well, but with today’s level of accuracy in manufacturing, we thought we could do better. A couple of great modern examples of dual-crown divers are the Longines Legend Diver and the JLC Polaris. Both are incredible examples of the evolution of the SC. For us, we wanted to do something a little more challenging. The Duality’s mid-case features dramatic chamfers that run along the top and bottom sides of the case. There is a slight-bowl shape to the case sides, which in combination with the complex chamfers, proves to be a real challenge in achieving our desired level of finishing.
After experimenting with over a dozen finishing techniques and processes, we finally landed on the perfect approach: a mixture of Swiss brush wheels and Japanese precision-polishing buffs. The brushed sections of the case feature the short and shimmery brush strokes that our watches have become known for, but the polished sections were impossible to achieve with standard polishing wheels. The way the high-polish sections come to a sharp tip presented a challenge in achieving the sharp lines and transitions that our customers appreciate. In order to achieve that we had to use a hard-edge polish wheel that requires less physical pressure, but a higher degree or skill and accuracy.
The concept behind the Duality is that a balance is struck when two equal and opposing forces coexist. The idea of twos and dualism is prominent throughout the entire design: two crowns, two bezel functions, two dial options, two-tone lume, two-layered dial, as well as the Duality emblem with contrasting finishes. We were probably destined to create this watch since the beginning of Nodus because even our own logo consists of two chevrons, intricately intersecting. And of course, that cycle wouldn’t be complete unless this brand was also owned and operated by two childhood friends.
There is very little information online about why EPSA closed up shop, but I’m willing to bet that if they were still around, there would not be nearly as much confusion regarding the Super Compressor design. Regardless, the heritage they left is certainly a very important one for dive watches and case manufacturing in general, but even more interesting is thinking about what role in history, if any, the Duality and Nodus might play in moving that legacy forward. A significant part of our brand ethos is to straddle the line between history and modernity, and with the Duality we tried to do just that: create a watch that respects its lineage but embraces its contemporary aesthetic and current place in history - and hopefully, if we are to go the way of EPSA, leave a lasting legacy for future watch companies to look back and improve on.
Wesley Kwok is the co-founder/operator at Nodus Watches. He is an entrepreneur by day, watch-geek by night, and a musician in the spaces in between. When he is not working or playing guitar, he can be found seeking out the best craft beer in California, perfecting his brioche bun recipe, or keeping up to date on the latest tech trends.
*This is part of the reason why many divers from the 50s and 60s were called “skindivers,” as they were not as water resistant as modern day 200m+ divers, and therefore was used only for skindiving, a form of shallower diving without the use of a dive suit.
** It is not known whether 100% of cases had the cross hatch pattern, but enough of them do have it, to a point where it can be a clear indicator of its authenticity.