There are several types of rotating bezels used for different purposes. We will explore various watch bezel types in this post. However, let’s start with how to use a rotating bezel on a dive watch as we are all about diving here on DiversDock!
ELAPSED TIME BEZEL
Divers use watch bezels to track elapsed time. Introduced by the Rolex Submariner and Blancpain’s Fifty Fathoms in the 50s, dive watches often feature rotating bezels to track time spent underwater.
The increments depend on the watch but go from zero to 60 minutes to track one hour elapsed time.
See on the Rolex Submariner image, the bezel has increments marked in numbers in tens and a marker for five minute intervals. From zero to 15 mins it has individual markers for each minute.
Divers line the zero marker up with the minute hand. Time elapsed during the dive can be tracked up to one hour.
As a safety precaution, most dive watch bezels can only move anti-clockwise.
If the bezel hits off something and the bezel is shifted, the time elapsed can only increase. Otherwise the diver may believe they have been submersed for less time and risk decompression sickness.
HOW TO USE A ROTATING BEZEL
- Using a rotating Bezel is easy.
- Simply wind the bezel so that the 12 O’Clock or zero bezel notch lines up with the minute hand.
- You can easily see the time elapsed by looking at what interval on the bezel the minute hand is pointing to.
- For example, in the Citizen image, 10 minutes have elapsed.
- Be ready to begin from the minute you set your Bezel
The highly popular and affordable Citizen Eco-Drive has a rotating bezel and a depth gauge. Dive watches with depth gauge are a rare species so to have that along with the rotating bezel on a quality watch is worth considering.
For more on scuba dive watches with depth gauge, read our post here.
Watch the Rolex video below to see how to read a watch bezel.
OTHER TYPES OF ROTATING BEZEL AND HOW TO USE
There are several other types of rotating bezel for various calculations. Let’s look at the most common types.
COUNTDOWN TIME BEZEL
Similar to the mechanics of an elapsed time bezel, which goes from zero to 60, the countdown time bezel counts down for one hour from 60 to zero minutes.
SECOND (OR THIRD) TIME ZONE
Also known as the GMT bezel, this type is used to track a second or third time zone.
This stems back to the 1950s when Pan Am asked Rolex to design a watch for their transatlantic pilots.
The GMT-Master was born and air crew were able to track both local time and GMT.
On the GMT bezel featured in the image here, blue indicates day and black indicates night in the second time zone.
Most commonly used to calculate speed, this type of bezel was born in the 1960s for the motor-racing industry. Found on chronograph watches, this type of bezel calculates units per hour.
It is commonly used to calculate speed but can be used for any activity that needs to track units per hour.
To use this type of bezel, start the chronograph as the car crosses a set line (eg. starting line) and stop it when it crosses another (eg. finish line). Units per hour (KM or Miles) can be then read on the watch bezel.
For detailed instructions on how to use the tachymeter bezel click here.
This type of bezel is the most versatile. Well nowadays we pull out our smartphone for time, compass, speed or any type of calculator. Imagine an analog watch that does all that!
These watches feature a logarithmic scale! Breitling were the first to introduce the slide rule bezel and later the Navitimer came to the market.
Used to calculate numerous mathematical calculations, the slide rule was traditionally standard uniform for pilots. They were able to calculate air speed, distance, fuel consumption and other measurements with this one tool.
For detailed instructions on how to use the slide rule click here.
Watch the video below to see how to use a rotating bezel on various types of watch.