The Most Common Watch Bezels and Their Functions

For tool watches, having complicated parts and features are standard. Take a dive watch as an example. The prominent part of most dive watches is the rotating bezel, aside from the other scales you see on the dial.  Whether it is the bezel or the scale, it is essential to know its corresponding functions, even if it is not significant to the wearer (if worn for aesthetics only).

Unknown to others, there is a hidden advantage to knowing how a bezel works and its types, especially if you consider it a powerful tool. For years, it remains functional and robust, just like the other timepieces, while serving its purpose for divers.

Types of Bezels and Dive Watches

If you are unfamiliar with what a bezel looks like, it is the part of the watch attached to the case, externally or internally. It rotates either clockwise, counterclockwise, or both.  Furthermore, it can be made up of different materials such as aluminum inlay or enamel.  

Rotating bezels are typical in dive watches but have varied functions depending on the kind of watch. These can be any of the following: general timer, elapsed time countdown timer, pulse rate timer, or even for timing and calculating the remaining fuel.  

There are different types of bezels you can see in watches, as follows:

For dive watches:

Count-Up Bezel

The usual bezel found in dive watches is the count- up bezel. It has a scale that goes from zero to 60, aligning with the minutes in an hour. This type of bezel is unidirectional to have an accurate estimate of descending or ascending of the diver. To use this bezel, you need to set the zero markers at the minute hand first as the time passes, read off elapsed time on the bezel.

Aquinus dive watches use count-up bezels making them ideal for divers. With this kind of bezel, divers can easily use it underwater, especially in determining their ascend point. It is never a problem for divers on how to use it since it is engineered for use without complication.

Countdown Bezel

It is like a count-up bezel with only one distinct difference: the minute track is reversed by going from 60 minutes to zero.  To use this, rotate the bezel so that the time remaining is set to the minute hand. Take note that when the minute hand reaches zero on the scale, the time is done.

For chronographs:

Tachymeter

Tachymeter is a standard scale found on fixed bezels with a chronograph. It is used to calculate units per hour or speed. Here is an example of how to use this for car speed. First, start the chronograph when a car crosses a set mark, then set the desired end mark and stop the chronograph when the car crosses that line.

Telemeter

It is like a tachymeter. However, instead of calculating speed, it calculates the distance for an event that can be seen and heard.

For medical use:

Pulsometer

Pulsometer is commonly found on specialized medical watches. Its design is like a tachymeter, but rather than tracing units per hour, it determines heart rate, with scales calibrated from 15 to 30 pulses.

Others:

GMT

This bezel is helpful when traveling, as it can both track another time zone and local time. In general use, the standard hour hand would be used for local time with a second 24-hour hand to line up with the hour on the rotating bezel (marked with a 24-hour scale).

Slide Rule

The slide rule is a complicated bezel. It does not require the use of the watch hands but uses a stationary scale and rotating scale. These scales can be used to perform several calculations. Pilots commonly use it in calculating airspeed, fuel consumption, and distance.