In response to several Questions and Inquiries about the use and availability of these bezels, I would like to shed some light on this subject.

Watches have always intrigued me and being of technical mind, I wanted to know how they worked and how to use them properly. I have owned Heuer Watches since 1966. They all have served me well and were used as TOOLS in my trade. There seems to be some confusion or lack of explaination on the use of and availability of DECOMPRESSION BEZELS. Here some Background and my experience on this subject.

In 1972, I purchased my Heuer Autavia GMT 1630. I ordered a Stainless Steel Band, spare 24 hour and Tachometer bezel as well a Decompression bezel from the Heuer Time Corporation in Springfield, New Jersey. All accessories like replacement wrist bands and bezels were listed in their catalog and are original factory parts.

In 1975, I purchased my Heuer Autavia GMT 11630 from a long time Heuer dealer in Zurich, Switzerland. While there, I also picked up a spare 24 hour bezel and a DECOMPRESSION bezel along with a Stainless Steel Band. Again all parts being original Heuer stock.

So we can see that these bezels were available from Heuer in the 1970,s and not just in recent years as some comments seem to indicate.
Here some Bezel Details : These bezels can be easily exchanged and mounted onto their respective cases but are NOT interchangeable between watches. This is due to the difference in the mounting diameter on the watch case and the plastic or mineral crystal on the watch. The 1630 bezel insert is slightly angled up towards the crystal whereas the 11630 is flat to match the mineral crystal. Both are shiny in appearance.
The Heuer Diver 100 is also different since it uses the 11063 Autavia case and employs a different design of the bezel and it's insert.

Now to the USE of the bezel: Being a PADI certified SCUBA diver, I could see how a DECOMPRESSION bezel would be helpful to determine BOTTOM times in a dive. With the easy changeover of the bezels, it was a no brainer. At that time, 1972, the only other watch that offered a decompression bezel was the DOXA Diver but I saw no reason to purchase another watch when Heuer offered an interchangeable bezel to serve the same function.
Here a couple of misconceptions: A scuba diver generally carries compressed AIR in his diving tank and NOT Oxygen. A decompression bezel is not a Depth Meter as implied in the Doxa write up. A diver wears a special depth meter on his wrist or on the instrument pod. The Bezel is simply a timing device to measure BOTTOM Time.
In 1972, Heuer published a guide which explains their chronographs along with the various features such as Calculators-, Pulsometer-, Tachometer- and Decompression Scales and how to use them. This was very basic, but a start.

Here an EXAMPLE of how the Decompression bezel should be used: The name is actually a misnomer. When a diver observes the bezel markings and surfaces at the proper time, he does not need to make decompression stops on the way back to the surface. The marking on the bezel originate from the FSSS, CMAS or the U.S.Navy Diving Manuals. They lay out the guidelines for safe SCUBA Diving WITHOUT decompression.
1. Generally, diving to a depth of 10 meters / 33 feet or LESS has no restriction on time spent under water.
2. Once we dive beyond the 10 meter /33 feet mark we must observe what is called BOTTOM TIME. This is where the BEZEL provides it's function.
Example; Lets say we want to take some pictures of a sunken wreck which is located at 115 feet / 35 meters below the surface. When starting the dive we set the RED
TRIANGLE marker on the bezel to match the MINUTE HAND on the watch. We dive down checking our depth as well as checking the minute hand. We take the pictures and
observe when the minute hand points to our depth of 35 meters on the bezel, thus telling us that it is time to surface. Our BOTTOM Time was approximately 20 minutes.
The RED 40 mark on the bezel reminds us that 40 meters is the maximum depth for SCUBA diving without Decompression stops on the way back to the surface. If this is not
observed we could end up with the "Bends" (to much Nitrogen in the blood) and we could be in serious medical trouble.
Note also that if you want to do another dive that same day or do multible dives, you must consult the Repetitive Dive Time Tables.
Keep in mind that Heuer used 600 meters as a starting reference for their Bezel Numbers. (This allows safe margin for diving in fresh water inland lakes). This gives a additional safety margin for single dives just about anywhere.

On a closing note I would like to mention that I have used the Decompression bezel many times and once I got back to do my day job (Flying Airliners) I changed my bezel back to the 24 hour bezel to tell me LOCAL TIME. Wonderful time pieces at work, Autavias are great, to all the Best, Heinz Rengel.