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:

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!

Best dive replica watches

I went out of my way not to make the obvious comparison between it, and the watch it replaces the Rolex Submariner 16610. I felt it was important to evaluate the watch on its own merits and to do so objectively, while setting aside my personal preferences. In this article, Im going to talk more about what I personally like and dont like about the 116610 relative to the 16610. In my mind, the 16610 is a high bar for any other watch even another made by Rolex to clear. It so perfectly strikes the balance between tool/sport watch, and dress watch. So many times people have asked or emailed me with the question which Rolex should I buy? My response is always the same: If youre going to buy one and only one Rolex, make it the 16610 Submariner. It has unmatched versatility making it the perfect choice for a daily driver.

I present for your inspection the Omega Seamaster Professional 300M 2225.80.00 2599.80.00 Chrono Diver. Every collector chases a dream early on in his career and often that dream doesnt jibe with what he or she really wants. You could dig Seikos and then see an Ebel that knocks your socks off. You could love Rolex and then see an Omega that you must have. This watch is my early collectors grail watch and I am happy to report that it is getting so much wrist time that I think I need to brush it down with rubbing alcohol because it is getting wrist stink.

I have no complaints about this watch. From its wavy face to its seahorsey back, Im enthralled. I wore this for two months straight and rarely put on any of my other pieces until they wrote a petition for my untoward attention. The Seamaster Chrono Diver is one of my favorites and, without a doubt, can be anyones favorite. It is timeless and beautiful and wears well with almost anything except true formal wear. It is an all-day watch and an real keeper.

Quality: 5/5
Style: 5/5
Overall: 4.5/5 Not perfect, but almost there.