No-timing-bezel divers

[Francois Boucher]

The issue of dive watches without a timing bezel has been discussed often, here, and in other forums. It has generated animated exchanges...

Many believe, with good reason, that a watch without a timing bezel can not be called a dive watch because it is not useful to sports divers, and does not comply with ISO 6425 & DIN 8306 standards. As a sports diver, I think they are right.

Others indicate that dive watches without bezels have been used in the past, and are still recognized as dive watches by diving professionals. An excellent website on dive watches includes a few models (1, 2, 3) that are not equipped with bezels (with the author's reasonable "standard disclaimer" about their limited usefulness to divers...). Some watch manufacturers (Panerai, Anonimo) still make no-bezel watches that they call divers. Is that reasonable? Yes: they are right too.

There is a fundamental difference between sports diving with a scuba apparatus, and professional deep, "saturation" diving. Their requirements for timekeeping are different.

Sports (scuba) divers have a limited supply of air, and they might have to follow underwater decompression procedures, if they exceed their no-deco time limit for a certain depth. The longer & deeper a diver stays underwater, the more nitrogen penetrates & dissolves in their body tissues (incomplete tissue saturation ensues), and this nitrogen in solution might pop into bubbles when the diver ascends and the ambient pressure decreases, much as carbon dioxide in solution within a soft drink bubbles up when the bottle, or can, is opened.

These divers NEED to time their dive precisely, and their depth, in order to be able to follow decompression procedures, that also need to be timed accurately. Unless they have a modern dive computer, sports divers NEED a watch with a bezel to time their dive, and their deco times.

On the other hand, professional divers, if they dive deep and for prolonged periods of time, are said to dive "at saturation". They use special gas mixtures with lowered nitrogen, oxygen (normoxic = 21%) and sometimes lowered oxygen concentrations (hypoxic trimix, such as 16% O2, because oxygen becomes toxic at high pressures and causes seizures and other problems), with other gases, such as helium or hydrogen, replacing the nitrogen & oxygen in the inspired air. The gas is fed to them through compressors & tubes, rather than being carried in tanks. They dive "at saturation", meaning that because they stay for extended periods at depth, their body tissues become saturated with nitrogen. In fact, they really have no time limit to their dive, other than that caused by the cold and local conditions, and do their deco inside decompression chambers on the surface.

The requirement for accurate-to-the-minute timing is not present anymore, because in any case, their body tissues are saturated with nitrogen, and they will need to spend a lot of time (days) in decompression at the surface. They do need to have some idea of the time, and a Helium-venting valve is necessary.

(Helium, a very light gas present in the deco chamber, infiltrates the tightest joints of the watch. While the pressure in the chamber is lowered slowly, the pressure of Helium within the watch may remain high, and the watch crystal might pop out or break if the Helium within the watch is not vented).

So, a timing bezel is not an absolute requirement for saturation divers. In fact, professional divers might not even be able to manipulate a timing bezel with their very thick gloves.

Thus, the Anonimo Professionale 2000, or Millemetri 1000 Hi-dive, with He-venting valve, really are to be considered dive watches and they might even actually be used by those Italian professional divers... for diving.

Other watches without a timing bezel, and without a He valve, (such as the Panerais) may be called dive watches, but the lack of a He valve creates a problem for saturation divers: the Helium may still be vented by unscrewing the crown, although this may allow humidity to enter the watch, and is really not optimal. These are not seriously designed for deep diving.

So, in conclusion: can a watch without a timing bezel properly be labeled a dive watch? Yes, if it was designed according to the specifications of deep, saturation diving. Is such a watch appropriate for sport diving? No, i don't think so.

There. I hope this is clear enough, that it helps clarify the subject, and that it will also decrease tensions in the forum! :-D

[XTrooper]

An excellent explanation and a much appreciated one, Francois. Thank you.

For the record, I would first like to apologize to anyone that I may have offended in any of my posts. This was not my intention. I also officially declare that in regard to "sports diving" that I was wrong and that, if you do intend to use a dive watch, it should have a bezel. My thanks again to Francois whose post explained this fact so well.

I hope the "Bezel Wars" can now end once and for all. B-)

[ripper]

François thank you for this explanation. I enjoyed reading this!

[Simon]

Yes, thanks Francois - a good summary & I enjoyed the link to the French site - just wish I could read n understand the comments.

X Trooper - you didnt need to apologise - but I respect your graciousness. This is a forum where full n frank discussion can take place - I enjoyed reading your arguments for why a bezel is not necessary on a pro diver watch, although useful & you do have some historical precedent.
It certainly made me think & made me re-consider watches like Anonimo & Panerai as serious dive tools.

Just one thing "what is a bezel?"

Grace

si

[redstart]

The issue of dive watches without a timing bezel has been discussed often ...

...

There. I hope this is clear enough, that it helps clarify the subject .... :-D

Thank's so much, François! Invaluable material there.

[Tragic]

I'd suggest this post go into the Reference sub-forum as well for the next time this rears it's ugly head.

[Nalu]

While Francois' conclusions are correct, his explanation is lacking somewhat. Let me expand:

There are roughly four categories of divers: recreational/sport, scientific/researchers/, professional/working divers and military/combat divers. Each of these categories has it's own diving technologies which it tends to use, though increasingly the lines are blurring these days. Specifically, the task at hand (mission, if you will) helps determine your dive profile (the dive you plan to do). Based on your dive profile and a few other considerations, the diver will choose his rig and gasses. I'll try to summarize the typical rigs and gasses below, but recognize that this is necessarily incomplete. There are entire books written on just bubble models for example. I'll note here that, regardless of the gas a diver is breathing, the only time you might need an HEV/HRV is during decompression from a saturation dive.

Professional (working) divers do more than saturation diving. They use SCUBA*, surface-supplied and other systems. There are relatively few sat divers out there working. Saturation diving is complicated, expensive and dangerous. It is a technique used only when required by the task at hand and only when the benefits outweigh the risks adn costs. All working divers have a dive supervisor and often a team of tenders who track every aspect of the dive. No watch is needed, since all times (ascent/descent/bottom) are kept by the surface team. A watch CAN be useful to a working diver as it lets him keep track of how fast he's working, how much time he's got left to finish the piece, etc. I'm reasonably sure that's why Anonimo do not include an elapsed time bezel on their professionally-designed models. It's simply not a requirement for the working diver, whether sat diving or not.

Scientific/research divers also use saturation diving, but rarely these days. More often some variant of SCUBA* is used. I don't have much interaction with the research community so I can't speak definitively, but I believe they also use a dive supe/tender system though probably not as formalized as in the working/military systems. I'd think that elapsed time bezels would be highly recommended, except when sat diving for the reasons Francois points out. As I stated, the line is blurring in modern times and recreational divers are becoming researchers as their technology improves. The Reef Project is one example, AME is another: http://www.marineexploration.org/?pg=Home

Military divers further sub-divide into combat and working divers. Military working divers use the same systems as commercial working divers and their SOPs are similar. Combat divers (and I'm including EOD in this group) use SCUBA* almost exclusively. Again, there's a Dive Supe for every op and he tracks bottom times (among other things). Each diver tracks also his own times, but not necessarily with an elapsed time bezel. On infiltration dives using a 100% O2 rebreather, bottom times can run into the hours and there is never a decompression requirement. A 60 minute elapsed time bezel is meaningless in this situation. Again, another case where a bezel is not necessarily a requirement for serious professional diving.

Recreational diving is familiar and I think everyone understands that you should at least have a dive watch with an elapsed time bezel when you dive. Again, recreational diving lines are blurring as technologies 'trickle down' from the research, professional and military fields.

I hope this aids in understanding. I wanted to bring out the point that the majority of commercial diving is not saturation diving and that there are cases where an elapsed time bezel is not needed for diving.

*SCUBA = Self-Contained Underwater Breathing Apparatus. This includes open circuit (OC), closed circuit rebreathers (CCR) and semi-closed circuit rebreathers (SCR). A wide variety of gas mixes can be used with many SCUBA rigs. For example, my SCR rig can handle air, NITROX, Trimix (O2/He/N2), Heliox (HeO2) or pure O2. Furthermore, I can switch gasses in the middle of the dive if necessary. That this is available to the qualified rec diver is still amazing to me!

[Francois Boucher]

Thanks for the clarifications, Colin.

Someone reminded me on another forum that water-resistant Panerais had been developed, in fact, for combat divers.

These professionals do not usually dive very deep, and frequently breathe pure Oxygen on rebreathers that release no bubbles.

Thus, these divers have no use either for a timing bezel.

[sharkhunter]

Francois don't take this post the wrong way (I'm not good with words or very subtle, so no offence meant :-X), but I'd like to add a could of points to your last statement below:
[Quote:] "So, in conclusion: can a watch without a timing bezel properly beccaled a dive watch? Yes, if it was designed according to the specifications of deep, saturation diving. Is such a watch appropriate for sport diving? No, i don't think so." [End Quote]

I'm only adding this so forum members (dive watch buyers) don't get confused and think they are buying a divers watch suitable for them to go recreational diving with.

Set standards ( ISO 6425 & DIN 8306 ) are there for a reason and if these say a "dive watch" needs a bezel, then here in the UK it would be against our Trade Description Act (the law) to call a watch without a bezel a dive watch suitable to dive with and this is in place to protect us, the consumer. So if Panerai or Anonimo tried selling a watch as a "divers watch" in the UK that doesn't conform to ISO set standards of what a dive watch is meant to be then they would be breaking the law and be prosecuted for it. They would have to sell these watches as sports watches rather than claiming they are "divers watches" suitable for diving.

Anyone here can call a watch what they like, but it doesn't make it something it is not and a manufacturer can't call a watch a "divers watch" if it dose not conform to set standards to protect us the consumer, regardless of a company's history or what saturation divers might use. So if it dosen't conform to set standards it is just a water resistant watch that some divers may have used.

If your going to take up scuba diving get a proper divers watch that conforms to these set standards that has been designed to do the required job or a dive computer (ideally both). Remember, it's your life at stake so use the correct equipment for the job and make sure you get trained properly.

[XTrooper]

Thanks for the clarifications, Colin.

Someone reminded me on another forum that water-resistant Panerais had been developed, in fact, for combat divers.

These professionals do not usually dive very deep, and frequently breathe pure Oxygen on rebreathers that release no bubbles.

Thus, these divers have no use either for a timing bezel.

I almost hate to admit this, but I learned about the "no bubble" rebreathers while reading a Dirk Pitt novel. :-D

Nalu: Thank you for the additional information. This is not only good information, but it's fascinating stuff as well!

I agree we you all that this material is definitely worthy of being archived and I have copied it to our Reference Material subforum. B-)