This is Why Dive Watches are Colored Red and Blue

Many dive watches are equipped with a bezel that is red and blue. The reason for the red and blue color is widely discussed in the watch community. However, there is one logic that stands above them all.

Dive watches have red and blue to indicate the maximum permitted bottom time for diving. The maximum dive is 15 to 20 minutes, depending on diving methods. Therefore, the bezel is red for the first 15-20 minutes to indicate the critical time.

The reasoning for the red and blue bezel has some different interpretations. The watch community (both newbies and veterans) has different points regarding the color of dive watches.

Why Dive Watches is Red and Blue

Many dive watches such as the Rolex Submariner and the Omega Seamaster is just one single color. However, Seiko is a watch brand that uses double colors for some of their dive watches.

There are some theories as to why dive watches actually have a red and blue color.

  1. The certified dive tables state that the maximum diving time at 30 meters is between 15-20 minutes. The 30 meters depth is what is considered the maximum depth for recreational diving.
  2. Water absorbs lighting, hence colors. Therefore, to separate the first 20 minutes, being the safe diving time, from the rest of the dial, the bezel is blue and red in color.
  3. Professional divers have up to 20 minters of decompression, and therefore, having a 20-minute timer essential.
  4. The red and blue bezel is made for decorative reasons.

The four different theories all have their own unique point. Some have a genuine feeling to the reasoning, and some don’t. Like, making the bezel red and blue purely for decorative reasons seems dumb.

However, what seems the most useful is the actually allowed diving time of 30 meters, with the coloring of the first 15-20 minutes of the bezel. The theories that make the most sense is the readability underwater, and the maximum allowed dive time since it concerns the safety of the diver.

Having a red and blue bezel on a diving watch allows the diver to see the elapsed time of a dive. Furthermore, with the red and blue coloring of the bezel, the diver can quickly indicate the remaining time of what is maximum recommended.

Deep diving
Deep diving

The certified (NAUI, PADI, etc.) dive tables state the maximum dive length to be 20 minutes at 30 meters depth.

Am I saying that the certified dive tables are why dive watches use a double color?

No, I’m not.

Am I saying that the only reason the bezel is red and blue is to make it more readable when diving?

No, I’m not.

However, there is no statement anywhere from any watch manufacture to why they have a multi-colored bezel. However, the 1-4 statements is the best guesses among watch enthusiasts.

When you think about it, the design of dive watches is a bit weird, ain’t they?

Most dive watches have a bezel going from 0 to 60 clockwise, hence counting up. In the picture below, the elapsed time is 38 minutes.

Seiko dive watch
Seiko dive watch

Some divers would prefer a bezel that was counting down rather than up. When the diver jumps into the water, the 12-hour mark on the bezel is aligned to the minute hand.

From there, the minute hand will count up, so the diver can, at a glance, see the time that has elapsed.

However, most divers know how long they will be underwater, hence having a bezel that is reversed would benefit the diver.

In such a setting, the diver would align the bezel’s 20-minute mark (the diver will dive for 20 minutes in this example) to the minute hand.

Now, rather than seeing the elapsed time, the diver sees the time remaining of his dive.

For divers that need decompression stops, the reversed bezel is also more useful.

Since dive watches have unidirectional bezels, the bezel only rotates counterclockwise. So when the minute hand reaches the 12-hour mark on the bezel, the diver can begin to ascent.

When the diver needs decompression stops, the bezel can be turned to count down the remaining time of the decompression stops.

The watch community’s theory states that the correct design is what we call the reversed/countdown bezel today.

However, due to the design and popularity of the Rolex Submariner has made the design of the count-up bezel the industry standard.

This is also why many believe that the majority of dive watches have a single color bezel, rather than the multi-color bezel.

Yet, if you look up the first-ever dive watch, made by Blancpain, it’s a count-up bezel. It can, therefore, be argued that the original design of the dive watches has been maintained.

Hereafter comes to the discussion of why dive watches are not innovated to be a countdown, rather than count-up bezels, and including the red and blue coloring to have better visibility of the watch when diving.

However, this, of course, comes down to 99% of dive watches are used as “desk divers.” Not a lot of dive watches ever see any significant water depths.

My personal dive watch has only been worn on the beach and felt the water from a shower. For my own sake, I can’t say that the watch is used to its full potential.

Do Divers Actually use Dive Watches?

The next natural question is whether or not a diver actually uses the dive watches.

Since we are a very developed species, using computers for everything, we have, of course, built computers for underwater usage as well.

Specifically, dive computers. The big difference between dive computers and dive watches is the features in the device.

Some divers use dive watches as redundancy to dive computers. However, the majority of divers is only using dive computers. Old schoolers and watch enthusiasts are more prone to using dive watches. Using dive tables, a dive watch can be just as good as a dive computer.

A dive watch can tell time and tell the elapsed time of the dive.

Diver wearing a dive computer
A diver wearing a dive computer

In contrast, dive computers can tell time, dive depth, monitor gasses, temperature, GPS-tracking, decompression time, etc. The features depend on the price of the dive computer, hence cheaper diving computer has fewer features.

There is very little purpose to using a dive watch if you already own a dive computer. The dive computer is much more advanced and can simplify the dive.

There are stories of watch enthusiasts that have used their dive watch because their dive computer broke during a dive vacation. Therefore, dive watches still work, and with the use of dive tables, a dive watch can be just as good as a dive computer.


Although there are many different theories, the most trustworthy is concerning safety and functionality.

The main theory of why dive watches uses red and blue is due to readability underwater.

Secondly, the red color for the first 15-20 minutes is that dive tables state that the maximum dive time for recreational diving is between 15-20 minutes.

Dive watches are cool, and to some extent, also very handy. You can use the bezel as an egg timer, time before a meeting, etc. You can find some very unique dive watches by different manufacturers, which is not your typical dive watch.

If you have a dive watch (or any other watch for that matter), you can learn how to keep it safe and in great condition. You will find all information needed in this post about maintaining watches.

If you have a dive watch and is unsure or curious about how a bezel is used, you can also check out this post.

Jonas Henriksen

AllInWatches is founded by Jonas, who has a great interest in mechanical watches. All aspects of manual and automatic (mechanical) watches is a big interest and have been a passion since 2015, where the first automatic watch was purchased. Seeing the transparent case back and discovering the heritage of watchmaking piqued an interest in horology.

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