I might be wrong here but I’d imagine that bezels on watches appeared when the first dive watch was invented in the 1950s—whether it be by Doxa, Rolex, or Blancpain. (We will never agree on who was first!) The dive time bezel is the perfect example of a truly-purpose driven piece of the watch design that has barely evolved in the past 70 years. It hasn’t because it’s as good today as it was back then. In this article, we will therefore talk about two major types of bezels and their functions, and two variants for each. And as we will see, people have come up with different ways to use these bezels that were not intended by their inventors.
Perhaps the most popular type of bezel, the dive-time bezel is—at least to me—the most recognizable type bezel. It appeared on the first dive watches as a way to make it possible for divers to track how much time they spent underwater. Most people dive for up to 45-60 minutes depending on how deep they go and how long they stay at their maximum depth. In general, dive-time bezels are count-up bezels, meaning they indicate how much time has elapsed. Divers needed to know (they no longer really due now that we have dive computers) how much time they had left (how much air their tanks had) before having to resurface.
Dive bezels come in different variations. Some are fully-graduated making timing an even precise, some only have full graduations for the first 15 or 20 minutes. Some don’t have any and only highlight 5-minute increments. I guess it all depends on how precisely people want to time events and of design preferences. Hardcore divers tend to have fully-graduated bezels to make counting the elapsed time easier. In some cases, like it is with pilot watches, the bezels are count-down, meaning that they go from 60 minutes to 0.
To be honest, I prefer count-down bezels on dive watches because I rather know how much time I have left rather than how much time I’ve spent underwater. Furthermore, dive bezels come with 60 or 120 clicks and can be unidirectional (rotate clockwise) or bi-directional (rotate in both directions.) I found over time that, personally, I prefer 60 click bezels that rotate in both directions because they are the easiest to use and are precise enough for everyday use.
The other type of readily available bezel of the GMT one. One easy way to transform any watch into a GMT is to add a 12-hour bezel. One can turn the bezel to align the hour hand to a different time zone, although one is limited by the fact that it shows 12 hours and not 24. Adding a 12-hour bezel is cheap and provides a different kind of usability depending on what we all need to do. Although these bezels do not have 24-hour scales, they are nevertheless called GMT bezels because they do help track time in a different time zone.
However, GMT watches do have a 24-hour bezel since the fourth hand, the GMT hand, does a full revolution around the dial every 24 hours. Therefore, GMT bezels with 24-hour scales are more useful. These bezels can either be fixed (in the case of the Rolex Explorer 2) or rotating (in the case of the GMT Master 2.) Furthermore, bezels can either rotate in one direction or two, and have either 24, 48, or120 clicks. We all have our preferences but I do prefer 48 clicks for a GMT bezel as it makes aligning the GMT hand to the bezel easier.
Other Bezel Types
There also exist other types of bezels that are less common. One type that I recently became familiar with is called the Bund bezel. Instead of having graduations to time an event up to 60 minutes, the bezel only has one marking (either a triangle or a hashmark.) This makes it possible to track elapsed hours instead of elapsed minutes and it is said that this type of bezel was first created for German underwater commandos who would spend more than 60 minutes under water. As you can imagine, these bezels had unique use cases which explains why they are rare.
Another type of rare bezel is the one that combines two different scales, generally a 12-hour and 60-minute scale. This gives the watch two purposes, for example timing a dive and then tracking a second time zone once the dive is finished. Doxa also made a type of dive bezel that combines a 60-minute scale and the indication of the required duration of safety stops before resurfacing. (The duration of the safety stops vary based on how long one was under water and at what depth.) As you can see, these more rare types of bezels had very specific uses.
What’s interesting to me is the various types of ways in which people use a dive bezel. Besides using it for diving—and again we don’t need them anymore but it’s cool to have one—people tend to use them to time an event, for example, how long they have been talking to someone on the phone or how long has the roast been in the oven. Again, we actually don’t need bezels to time events anymore since we have smartphones, but if you are like me, you find it easier to turn the bezel on your watch than to reach for your phone and set a timer.
In other words, bezels on watches have been around for more than 70 years because they have always been very useful. They first helped keep divers safe and now we can use them as we do a chronograph: to time events. In other words, bezels are still very practical and they give any watch a utilitarian aspect that many of us adore. (I for one do!)