Watch bezels – the ring around the edge of the watch – are often chosen for their looks. Many watch owners don’t know what the bezel on their watch is for. This is a pity because the bezel is actually useful if you know how to use it.
They are not mechanically linked to the watch mechanism, making them a simple and reliable way to add functionality to the watch. We will look at the purpose of the different types of bezels.
They can be used as stopwatches, time-zone converters, and even currency converters. While digital LCD watches and smartphones offer similar or better functionality, the simplicity of a rotating bezel makes it attractive for daily use. Just grab the bezel and turn the dial. Seeing the distance between the points on the bezel, their spatial relationship, also gives you an intuitive feel for the values, that is missing in a digital display.
Most bezels are “outside” the watch casing itself. You don’t have to worry about compromising the waterproofness of the watch when you turn the bezel. (Compare this with push-buttons on watches, which usually can’t be pushed under water.) Some watches have the rotating bezel inside the watch. The bezel is rotated by turning a small knob on the watch.
While some bezels work with the hands of analog watches (quartz or automatic/mechanical), other bezels work independently and can be found on digital watches as well.
The rotating bezel can be removed for cleaning or replacement. Search YouTube for instructions for your brand and model of watch. The bezel should turn easily. If it doesn’t, try a drop of light mineral oil.
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Dive Watch Rotating Bezels
These are the most common bezels, and probably the most useful. The bezel is simply a copy of the standard 60 minute watch face. The classic dive watch design is the Rolex Submariner. Some bezels are purely decorative and don’t rotate at all. These should be avoided.
To use the bezel as a stopwatch, turn the bezel until the bezel’s zero position (60 minute position) lines up with the watch’s minute-hand. You can now read off the elapsed minutes by looking at where the minute-hand points on the bezel.
This won’t give you to-the-second resolution, but is accurate enough for timing many daily tasks – cooking, exercising, food orders, car park meter duration, break times. To time durations of more than an hour, align the bezel to the watch’s hour-hand instead.
The bezel should rotate in the anti-clockwise direction only (unidirectional). This is because this design was originally used to time underwater dives, to avoid diving too long and running out of air. (Scuba divers now have an air gauge to show how much air they have left in the tank, but still use a dive watch as a backup). If the bezel was accidentally knocked, the indicated elapsed time would increase, not decrease, which is safer because this would cause the diver to cut short his dive instead of staying too long.
On cheaper dive watches, there are 60 bezel click-stops for one complete turn – one click for each minute on the bezel. More expensive dive watches have 120 click-stops, allowing for more accuracy in lining up the bezel to the watch’s minute-hand.
To allow the bezel to be read in the dark, the zero marker on the bezel should be luminous. Some dive watches have luminous hands but neglect to make the bezel luminous too.
When choosing a watch, look for a clean and uncluttered bezel that can be easily read with a quick glance. Many bezels mark the zero position with a triangle to make it easy to find.
One unconventional use of the dive bezel is as a dual time indicator. Let’s say your time zone is 4 hours behind GMT (GMT minus 4). To set the bezel to indicate GMT, turn the bezel so that the zero mark is 4 hours before 12 o’clock – which is 8 o’clock. You can now read off the current time in GMT if you take the bezel as the watch face.
Tachymeter Watch Bezels
Tachymeter bezels are the second most common bezel found on watches. Unfortunately, they are not as useful as dive watch bezels.
They are used to convert time (in seconds) to speed per hour. They work best with analog chronograph watches – watches where the seconds-hand is used as a stopwatch.
The dial starts off with “1000&Prime near the 1 o’clock position, or “500&Prime or “400&Prime between the 1 o’clock and 2 o’clock positions on the watch face. The numbers decrease (non linearly – the numbers decrease more slowly) going clock-wise around the face of the watch and ends up with “60&Prime at the 12 o’clock position.
Let’s say you are in a car or train and you just pass a mile marker. You start the stopwatch, then stop it when you pass the next marker. The seconds-hand will now point to your speed. If the seconds-hand points to “80&Prime on the tachymeter dial (9 o’clock), you are traveling at 80 miles per hour.
If those were kilometer markers instead of mile markers, your speed would be 80 kilometers per hour. If you were timing an action, say the time taken to chop a log of wood, then the wood-chopping speed would be 80 logs per hour.
The tachymeter dial doesn’t have to rotate and is sometimes located inside the watch case, behind the glass crystal window. This means that one watch can have a tachymeter dial and a dive or other type of rotating bezel.
Some watches have more than one tachymeter dial. A second dial (60 to 30) is for timings between 1 and 2 minutes. A third dial (30 to 20) is for timings between 2 and 3 minutes.
Tachymeter dials are sometimes found on non-chronograph watches. To use these as a tachymeter, the tachymeter bezel needs to rotate. To start the timing, quickly turn the bezel so that the “60&Prime position on the tachymeter dial is aligned with the watch’s seconds-hand. You can’t stop the timing. Instead, eyeball the seconds-hand’s position on the tachymeter dial and memorize the number, when the timing stops.
Aviator or Flight Watch, Slide Rule Bezels
Aviator (also called pilot or flight watches) have a circular slide rule bezel. You can make quick multiplication and division calculations with it, to 2-digit accuracy. While this might seem unnecessary in this age of electronic calculators and smartphone apps, a slide rule on your watch makes currency conversions and price discounts easy to calculate, as shown in the YouTube video below.
The slide rule scale runs from 10 to 90 or 1 to 9 (both will work – when using a slide rule, you need to mentally convert the tens anyway so that you can work with hundreds or thousands or decimal fractions) in a non-linear (logarithmic) scale – the scale between 10 and 20 is large, and gets smaller all the way to 90. Some watches place the 60 on the slide rule at the 12 o’clock position, others place the 10 there. The actual position doesn’t matter.
Unlike a dive watch bezel, the slide rule bezel is smooth and does not click – to allow for fine adjustments. It also rotates in both directions.
These are sometimes inaccurately called E6B watches. The real E6B circular slide rule is used in pilot training and has more scales than can be fitted onto a watch face.
World Time Watch Bezels
World Time (sometimes called GMT) bezels are designed to help you easily convert the time in one time zone to another. Some designs use an inner (behind the watch glass crystal) rotating ring instead of a rotating bezel.
The bezel, or sometimes the inner rotating ring, is divided into either 12 or 24 hours and marked with the names of cities in each time zone. Seiko has instructions on how to use the two different types (bezel with city names – 24 hours, inner rotating ring with city names – 12 hours).
The 24-hour bezel works together with a non-rotating 24-hour dial. Names of major cities of the world are printed on the bezel. Let’s you are now in Japan (GMT plus 9) and it is 7pm. Turn the bezel until Tokyo points to 19 on the 24-hour dial. To see the GMT hour, find London on the bezel and then read off the corresponding hour on the 24-hour dial.
The 12-hour rotating ring makes it slightly easier to set – just turn the rotating ring until Tokyo points to the watch’s hour-hand, find London on the bezel and then read off the corresponding hour on the 12-hour rotating ring.
The 24-hour bezel is less confusing because it is easier to see where the am/pm and international date line (meaning a different day) transitions are. Hint: the international date line is near New Zealand (Auckland or Wellington is usually marked on the bezel).
Instead of a bezel with names of cities, some watches use a fourth hand that automatically tracks the hours of a second time zone (this hand can be set independently from the watch’s main hour-hand).
Watch Bezel Materials
The material used to make the bezel will affect how well the bezel stands up to abuse. Ceramic bezels are the hardest and resist scratches well. They are found on luxury watches that cost thousands of dollars.
Mid-price watches (hundreds of dollars) have a stainless-steel bezel. The markings should be engraved for long life, not simply painted on. Paint-filled engravings combine the longevity of engravings with the high-contrast easy-to-read usability of painted markings.
Cheaper watches have a plastic bezel. While softer and easier to scratch than stainless-steel, they can be easier to read. For long life, the markings should also be engraved.