Whether you have just purchased a dive watch, or you are in the market for a dive watch, you will need to know how to use it. You will need to know the different components, features, and mechanisms that make the watch work so that you can use the watch to its maximum potential.

Before diving in (see what we did there?) to the details of how to use a dive watch, we need to know the different parts of the dive watch and how to read what the dive watch is telling us. This is the first step to help us understand how to use a dive watch.

The Basic Parts of the Dive Watch

First things first are the parts of the dive watch. The dive watch is made of different mechanisms, features, and displays that will help you have a safe and efficient dive. This is what makes knowing how to read the dive watch so important. Knowing the different parts of the dive watch and how to read it will help you understand how to use a dive watch.

The Case

The case of the watch is the external shell of the watch. It is what keeps the internal mechanisms safe and protected. The case of the watch is a durable material that will withstand the pressure and impacts of diving. The case should provide a minimum water-resistance of 100 meters.

The Band

The watchband or strap of the watch is connected to the case and should sit comfortably yet securely on your wrist. The watchband may be made of rubber, plastic, or another durable material that will be comfortable while it is kept in place.

The Rotating Bezel

The rotating bezel is what makes a dive watch a dive watch. The most basic dive watch will have a rotating bezel. The rotating bezel is the mechanism on the watch that rotates from 0 to 60 to count the minutes you are spent underwater.

The bezel will have increment markers, usually in increments of 5 or 10 minutes, with the first 15 minutes marked in one-minute increments. This helps the diver know the exact moments to make decompression stops, as well as know the exact time they have spent underwater with no second-guessing.

The Movement

For the dive watch to function, it will have to be powered. The watch can be powered by quartz (battery) or automatic movement. When powered by quartz, the watch will take the energy from the battery to electrify the quartz, causing the secondhand to tick.

An automatic movement watch will wind the spring of the watch as the watch is worn. The energy is stored in the spring and distributed to make the secondhand tick. Automatic watches don’t require a battery, which sometimes makes them more desirable than quartz diving watches.

The Water Resistance

A dive watch must have a water resistance of at least 100 meters (330 feet) to be certified for diving. If the watch is not water-resistant to 100 meters, it is not a dive watch and is not recommended for diving.

The Illumination

A dive watch must be luminous in dark conditions to be able to see the reading on the watch. You don’t have to be submerged very deep to need assistance reading the numbers and indicators on a dive watch. Having a backlit face or illuminated numbers will allow you to see the watch in dark or murky conditions. A dive watch must have some form of illumination to be certified and used as a dive watch.

Optional Features of the Dive Watch

There are additional, optional features a dive watch can have to make your dive more safe, successful, and efficient.


A tachymeter on a dive watch will measure the speed of your dive over a set distance. You will need to know the exact distance of the dive to know your exact speed. The tachymeter scale typically begins at the 7-second mark with a unit measurement of 500; however, the scale may start before or after this point. It just depends on the style of the watch.

600 units = 6 seconds

500 units = 7 seconds

400 units = 9 seconds

To understand how to read a tachymeter, you need to know what the numbers represent and how the math works. The good news is that the tachymeter does all the calculations for you on the bezel. However, if you don’t know what you’re looking at, this feature can be rendered useless, which is why it is important to understand how a tachymeter works.

There are 3,600 seconds in an hour. To know the speed you went when traveling a mile, you will take 3,600 and divide it by the number of seconds it took to travel the distance. However, you will likely only be diving a fraction of this distance, so you will need to know how to adjust the tachymeter scale according to diving.

Let’s say a diver needs to measure his speed when swimming ⅛ of a mile. He begins the swim and enables the tachymeter when he crosses point A. The tachymeter stops when he crosses point B, giving him a tachymeter reading of 45 seconds, which is 80 units based on a one-mile distance.

You know that the swimmer did not 80mph, so you need to adjust the speed according to the distance you traveled.

To do this, you will need to adjust the number of seconds that are in ⅛ of an hour. ⅛ of 3,600 is 450 seconds. This will replace the 3,600 in the original one-mile equation.

Four hundred fifty seconds divided by 45 (the number of seconds it took to complete the dive) is 10. This means you swam at a rate of 10mph.

The tachymeter is designed by default to measure a one-mile or one-kilometer distance in one minute. Therefore, if your distance is shorter than one mile or one kilometer, you must adjust accordingly.

Helium Valve Release

Saturation diving is when you dive for extended periods of time in conditions where helium and other atoms have saturated the atmosphere. Helium atoms are small enough to enter the dive watch. This can cause pockets of pressure to become stuck within the watch. This is an issue when the watch becomes depressurized.

When the watch is depressurized, the pressure that is built up inside the watch between the helium pockets will not be able to escape. This can cause the watch case to break and the gears inside to malfunction.

To prevent the watch from pressure buildup due to pockets of helium that are stuck within the watch, the helium will be released through a helium release valve.

A helium release valve will automatically release any helium within the watch so that pressure does not build up inside the watch and cause it to malfunction.


Some dive watches are equipped with alarms that sound when certain functions are performed.

When ascending to the surface, a dive watch with a deep stop alarm will sound to let you know to stop and take a 30 to 60-second rest during ascension. Making period stops during ascension will help your body during the depressurization period. Ultimately, your body will not become as fatigued during the depressurization period because it has had time to slowly depressurize while ascending.

Digital vs. Analog

Many dive watches are analog. They have a rotating bezel with a day, date, and time display, and a chronograph. A chronograph is another word for a stopwatch. It will show the second, minutes, and hours of elapsed time.

Digital dive watches may also be known as a dive computer. A dive computer will gather information about your dive and relay it back to a computer interface.

How to Use the Dive Watch

Now that you know the different components and features of a dive watch, it’s time to put it to use.

First, you will need to know how to set the bezel. The bezel will be what keeps track of the time you spend underwater, so it is imperative to set it correctly before you begin your dive.

To do this, you will need to set the bezel to zero and line it up with the watch’s minute hand. This will tell you how much time has elapsed during your dive.

One of the most important and often overlooked aspects of the dive watch is care and maintenance. To get the most out of your dive watch, you should clean it after each dive. All you need is a little running water and a soft cloth to rinse out any residual sand and saltwater that may have gotten caught in the watch. Try not to scrub the watch as this can cause the watch face to scratch.

Take your dive watch to a horologist or jeweller at least once a year to ensure that all of the gears and mechanisms are working properly.

Understanding the different parts of the dive watch and keeping the dive watch well-maintained will not only help you understand how to use a dive watch correctly, but it will also extend the lifespan of the dive watch you choose.