Cenotes and Cave-vs-Cavern
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bamamedic
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Since no one had mentioned the "cover your light" rule in this thread, I thought it was worth mentioning. My work computer tends to stall up when I open multiple pages, so I didn't get a chance to review your link. My cavern instructor mentioned that covering your light was a good way to check to see if you're still in the cavern zone, in addition to following the various other rules. So far, it has worked pretty well for me...I can't say I've ever ran into a situation where there was light filtering in from a small crack...I've just always looked for the gigantic glow coming from the cave entrance, and if I don't see that anymore, than I know I'm past the cavern zone.
bamamedic
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Like I said...work computer sucks...can't open multiple pages without crashing Internet Explorer. The "cover your light" rule is taught in addition to the other rules of depth, distance, gas management, and visibility as a quick check to see if one is still in the cavern zone, assuming you haven't violated the other rules.
OP, the best advice I can give ya is that it might be a fantastic idea to become Cavern certified. It's usually only a two day course, it's fairly inexpensive, and most instructors will let you take it in standard recreational gear.
I still don't think you are getting it.
There are caverns where you can easily be more than 200 linear feet from the surface, or more than 130 feet linear from the surface in typical recreational gear, and still see the "glow" of the entrance, but by Cavern and Cave diving definitions going past the 200/130 foot linear distance makes it not a cavern dive.
There are also caverns where you are actually out of sight of the "glow" of the entrance and can not yet see the "glow" of the exit, yet there is enough light from the small cracks above that one does not even need a light, yet by definition it is not a cavern dive.
I am pretty sure the first example above exists in the cenotes and I have been in quite a few of the second example here in Hawaii. Just because you have never encountered such a dive is hardly reason to go around thinking you know all there is to know about the definitions of Cavern/Cave as used by the Cave Diving agencies.
Did you read and comprehend the NSS-CDS typical recreational dive gear cavern definitions I posted earlier in this thread?
halemano, I will stand by my statement that IN GENERAL, untrained divers don't belong in overhead environments. That said, I have dived the Cathedrals in Lanai, and other than someone running out of gas inside and panicking and bolting, it's hard to see how anyone could get into trouble in a very large space with a heavy sand bottom and multiple exits and tons of light. I'm sure we can all pick specific examples of overhead environments which are relatively benign, but I also don't think it's at all good to encourage divers in general to think that entering a generic cavern without any training is a good idea. We have lost several divers this year who entered overhead environments without the appropriate preparation -- it's a pretty horrible way to die, in the dark or the fog, lost, scared, and knowing you are running out of breathing gas. Do you take issue with this?
The majority of charter operators and many shore operators in the State of Hawaii conduct guided overhead dives with guests who have no overhead training. By using the word tour in my post directed at your quote using the word tour I was trying to limit my contention to your apparent generalizations about tours.
If you look back at all our previous posts along this line of thought, I'm of the opinion that "in general" when one of your posts is challenged you tend to "huff and puff" and exaggerate while blowing smoke and using mirrors.
Did the panicked diver actually have NO air in their tank?
Some of us have a different definition of running out of air than you I think;
TSandM's Diving Maui Blog:
bamamedic
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I believe you may have not fully read my post...what I believe I said was that in addition to following the other rules (rules of depth, rules of air management, rules of penetration distance, etc), that covering your light to check to see if you're in the cavern zone is one way of making sure that you're still in the cavern zone. There are indeed deep caverns, and I mentioned that one needs to follow the other rules as well. Simply checking with your light doesn't guarantee that you're within depth or penetration limitations. Whether you're still within depth or penetration or air management rules is up to the diver and how well her or she has been paying attention to his or her dive.
I don't believe that at any time I said I know all there is to know, I simply relayed from my experience that I haven't ran into that particular situation myself.
OP, are ya still around?
halemano, I'm almost speechless.
Peter didn't run out of air, he hit minimum gas and went up. I phrased it poorly; I was a very new diver at the time.
I'm very sorry if you think I disparaged Hawaiian guided dives through things like the Cathedrals. I started to expand on that, but whatever I write, you are going to take issue with.
Peter didn't run out of air, he hit minimum gas and went up. I phrased it poorly; I was a very new diver at the time.
I'm very sorry if you think I disparaged Hawaiian guided dives through things like the Cathedrals. I started to expand on that, but whatever I write, you are going to take issue with.
TSandM, my poke at your out of air post evidently went overhead; on a tour, with a guide, no one will be out of air. They might get below the briefed pressure for exiting the cavern, or even below the briefed pressure to go to the line, and they might just panic, but using out of air when the discussion is concerning guided cavern diving is going a little over the top.
And then you close with this statement, "We have lost several divers this year who entered overhead environments without the appropriate preparation -- it's a pretty horrible way to die, in the dark or the fog, lost, scared, and knowing you are running out of breathing gas. Do you take issue with this?" How is that not completely over the top for a thread discussing guided cenotes/cavern diving?
So I went completely over the top to show you how it feels.
I have been trying to keep the discussion to REAL definitions of cavern diving according to Cave Diving Agencies and the other topic in the OP; guided cavern/cenotes diving. If you were able to stay on topic and answer legitimate questions from other members then I would have no issue with what you post.
And then you close with this statement, "We have lost several divers this year who entered overhead environments without the appropriate preparation -- it's a pretty horrible way to die, in the dark or the fog, lost, scared, and knowing you are running out of breathing gas. Do you take issue with this?" How is that not completely over the top for a thread discussing guided cenotes/cavern diving?
So I went completely over the top to show you how it feels.
I have been trying to keep the discussion to REAL definitions of cavern diving according to Cave Diving Agencies and the other topic in the OP; guided cavern/cenotes diving. If you were able to stay on topic and answer legitimate questions from other members then I would have no issue with what you post.
I'll make one final effort to clarify.
What I said about the Cathedrals was that you'd have a hard time getting hurt in them. I posited an extremely, wildly unlikely circumstance to show that something really out of line would have to happen before they were an unsafe environment.
I think the original poster's question was only very partially about the formal definitions of and distinctions between cave and cavern, and much more about whether the cenote tours, being that they are in true overhead, were justifiable or safe. That was the question I tried to address in my answer. I think they are safe when the rules are followed, because their history tells us they are safe. I do not think it is safe for open water trained divers to swim into caverns as a general rule. People do die that way. I think it is the general position of the agencies that teach diving, whether it's open water or cavern/cave, that untrained people should not be in overhead environments. Certain very well defined exceptions are tolerated. The cenote tours are one of those exceptions, as are dives like the Cathedrals.
What I said about the Cathedrals was that you'd have a hard time getting hurt in them. I posited an extremely, wildly unlikely circumstance to show that something really out of line would have to happen before they were an unsafe environment.
I think the original poster's question was only very partially about the formal definitions of and distinctions between cave and cavern, and much more about whether the cenote tours, being that they are in true overhead, were justifiable or safe. That was the question I tried to address in my answer. I think they are safe when the rules are followed, because their history tells us they are safe. I do not think it is safe for open water trained divers to swim into caverns as a general rule. People do die that way. I think it is the general position of the agencies that teach diving, whether it's open water or cavern/cave, that untrained people should not be in overhead environments. Certain very well defined exceptions are tolerated. The cenote tours are one of those exceptions, as are dives like the Cathedrals.
