Hey Doc,
Nice to have you here. I would like to comment on some of your posts.
I was prompted to write my post after reading yet another story of a lost cave diver in today's paper.
The man who was lost, was NOT a cave diver. He was simply a OW diver who wanted to see the inside of a cave. Just like an extremly high percentage of ALL cave fatalities.
Decompression diving without a chamber on site, penetrations of any sort in scuba, deep air diving, etc
A chamber on site at every cave, with trained professionals to use, would be a waste of money. It would be like trying to outfit every dive charter boat with a mobile chamber. It simply is not realistic. I do not know the exact figures, but I am willing to bet that you have more DCS hits from typical recreation divers, than you do from trained tech divers.
As for penetrations with scuba, it has been done hundreds of thousands of times by TRAINED tech divers, without a problem. Yes, things can happen, and they do. However, those thing happen in commercial diving too. Should we simply ban all diving because bad things can happen?
Oh, and on the subject of deep air, you will find that many tech divers are against it.
It's like scuba divers who penetrate the Andrea Doria to get one of those coveted pieces of "Italia" china. Lots of folks have died doing that. Is the China worth it?
You didn't happen to just read "Deep Descent" did you? Anyway, many divers travel to the Doria without incident. However, in a high risk environment, things do happen. If trained properly, a person with the right mental capacity can make hundreds of dives to the Doria and recover lots of China without problems. Just as a properly trained driver can drive hundreds of thousands of miles without incident, but could have been killed at any time. Was the trip to grandma's house worth it?
As to fouling umbilicals and cutting hoses, asked by other posters, dive hose is incredibly tough and fouling isn't usually much of a problem. Generally easier to handle fouling problems without the constraints of limited breathing media. Penetrations with surface air are pretty routinely done at around 1000' length and much farther using special umbilicals from time to time.
Fouling may be easy to handle with an umbilical cord, but without the umbilical cord, their is no fouling to worry about. In the cave, their are things we call line traps. These are areas where you could not fit even your arm into, but a hose could. They can be quite a few feet deep. If you were to turn a corner in a cave, and the umbilical gets caught in a line trap, you are pretty much screwed. Pulling it out, might not be an option as it could be jammed in something inside the line trap.
A 1000' penetration is impressive. However, in cave diving, that is considered a "I want to burn off the rest of the gas in my tanks dive". I have gone 1800' in and another 1800' out and only used a total of 1/3rd of my backgas. Following the thirds rule we use (1/3rd gas in, 1/3rd out, 1/3rd for emergency) I can go over 3000'. Add a stage bottle or two, and I could extend that to 6000'. Add in rebreathers, and anything is possible. I ask, do you know where you can find a 18,000'+ umbilical? That is what the team from the WKPP (Woodville Karst Plains Project) would have needed to do one of their last dives.
Now, who'll step up and admit that hey, there just might be some safety advantages in having unlimited breathing media and surface comms and support when you're deep into a penetration? Anyone? Hello?
I am willing to admit that an unlimited breathing media, surface support, and comms would be great. However, we simply do not have the ability do do that as of yet. The closest thing we have to unlimited breathing media, that would be suitable to a cave environment, is a rebreather. However, even those have limitations. That is why we plan our dive, and dive our plan. That is why we only use one third, or less, of our available gas to penetrate. So we have the ability, and the gas, to handle an emergency.
Surface communication would be great. However, as stated before, it is not suitable in a cave environment. It simply will not work. Find the technology to make it work, and I am sure we would adopt it.
Surface support in general is a great thing. For the long exploration dives, it is vital. Many dive teams go in and out to help stage bottles and check on divers at different penetrations. They are usually very well planned dives. I would suggest that you visit
www.wkpp.org and read about their dives. You will see the planning that is put into something like that.
Is EVERY friggin cave likely to suffer irrepairable damage from a mere tended umbilical (which is nearly neutrally bouyant, anyway)?
Yes. Even with a nuetrally bouyant umbilical, the line will drag the floor in some places simply because of turns, and sudden depth changes. Inside a cave you can have drop off that goes straight down for quite a few feet. The umbilical would drag against the clay floor and the soft limestone, and yes damage would be done.
Often, safety is a result of redundency. In commercial air and gas systems, this is often represented by a surface supplied umbilical and a bailout rig
In cave diving our redundancy is, to name a few; using one third of our available gas, using two first stage regulators on seperate isolated valves, spare masks, three lights, etc. We even have redundancy for our brain, our buddies.
Often, they do this stuff every day and just like recreational divers, have to consider peer pressure and the "macho" aspects of the job.
And so do cave divers. However, we have to be smart enough not only to not fall for peer pressure, but not to make any pressure for anyone else. Not to allow anyone else to go beyond their training and comfort level. That is why we have a golden rule; Anyone can turn a dive at anytie for any reason. No questions asked.
That's OK with me, but then why is it that if a film maker wants to drag THREE umbilicals into a cave for LIGHTING, that's OK, but when I suggest that divers drag one LIFE SUPPORT umbilical into a cave, I'm suggesting some sort of environmental travesty?
Because special care was taken in the routing of the cables, and other were used to hold the cables to avoid damaging the caves. I can say that I know for a fact it would be impossible for me to find 18 divers to hold my umbilical, and each others, simply so I could do a 1800' dive.
Are rock formations more important than human life? If they are, should ANYONE be permitted to dive in a sacrosanct cave? Maybe NO ONE (gasp) should be allowed into caves (unless they subscribe to certain enviro-cave-priesthood-diving cabal strictures). It strikes me as evident that even the best-trained cave diver might accidentally strike a rock formation with metal diving equipment.
NO. Rock formations are not worth a human life, and I do not understand where you get the idea that we believe that. Yes, even the best trained cave divers hit a ceiling or floor occasionally, however, most of us feel bad about that, and train extensively to minimize the chances of that happening.
As to 0 vis if you accidentally touch the bottom in a cave and kick up silt as some posters have stated, most of my working dives have been in 0 vis. Don't cave divers train for that? If not, what are they expected to do if they can't see? I admit that I don't understand the concern here. You're in deep sh*t if you can't see? That strikes me as another case for the umbilical...
I understand that most of your work is in 0 vis, however, zero vis in a cave just ain't fun. What are we going to see? Why bother going in if we can't see. If I want 0 vis, I do not need to go in a cave, I can go to the Chatahoocee River.
Oh, and yes we do train for that. We train a LOT for that. In fact, we go back in a cave, turn of our lights, and try to find our way out. Most of us even practice this drill after training is over. We have to learn how to get out, and condition ourselves not to panic. A trained cave diver is not in deep guano if they can't see, they are simply inconvienced, and forced to exit the cave, cutting the dive short.
All of this strikes me as a case against the umbilical. If the umbilical drags the clay and silts out the cave, we must leave. Dive over. That sounds no fun to me.
Can anyone tell me how the inability to make a free ascent in a cave differs in the least -- in a safety and life-support context -- from the inability to make a free ascent in any other environment? If it is different, I want to know why. If it's not, then I also want to know why different safety protocols should pertain which are specific to caves as opposed to wrecks, pipelines, intakes, outfalls or structures?
In some cases it's not, in some cases it is. Penetraitons in caves are generally further than in wrecks or pipelines. The different protocals are because the environment itself is different.
In a related vein, how is decompression diving without a chamber available somehow safe for recreational divers, but VERBOTTEN for comm divers. Those bubbles must be very selective in picking their victims. You think those bottles hanging under the boat are a safe substitute?
I beleive I touched on this already. The thing is, we see things different in tech diving then in commercial diving. We beleive in preventing the bends by using different gases and ascents. We are extra careful not to get bent. We are trained not to get bent. Where as in commercial diving, it is basically, opps, I am bent, let's hop in the chamber. No, I admit, I do not know about commercial diving, but it is my understanding that you would use the chamber for your decomression, whereas we use deco gasses. It may not be as safe as having a chamber on site, but it is a LOT more practical, and has an excellent track record among, once again, trained tech divers.
Then the cave diving community can excoriate me for not understanding how CAVE DIVING -- as opposed to any other type of diving -- is above and beyond common sense, gas laws, diving physics, and the ability to successfully hold ones breath indefinitely.
It's a hole in the ground underwater. You can't make a free ascent. You have limited breathing media. Maybe you can't see anything. Maybe you'll get lost and disoriented. You've got to be careful not to bump into a rock for enviro reasons and you might have to wiggle through a hole or two. What am I missing?
No one has said that we are above and beyond common sense, gas laws, diving physics, etc. Only you have said that. We are in two completely different environments, for different reasons, and with different goals. This calls for different equipment. I do not understand why this is so difficult to understand.
This ABSOLUTELY SCREAMS for surface gas supply, comms and support and because the scuba industry doesn't support it -- and you guys aren't taught it -- you develop your own scuba protocols and methods to do the work.
Again, these items simply are not refined enough for use in cave systems. As for what we are taught, you have to understand that we are not taught by the general mainstream scuba industry. Far from it. We have specialized gear, and specialized techniques for what we do, just as you do. If you feel our safety record is bad, then I suggest again you look towards the WKPP. They have a zero fatality rate since George Irvine took over an implemented strict guidelines. Can your industry say that? Maybe you guys need to rethink your methods and become DIR divers.
I understand the dynamic and can honestly respect the skills required, but reiterate that it's not the only way or the best way.
It might not be, but so far, no one has developed a better way. Heck, yours might not be the best way for your job either.
They're safe, they're proven and a lot of it is not all that expensive as compared to dive vacations in exotic locales.
Again check out WKPP. Our methods are safe and proven. Even non DIR cave divers have an excellent safety record. As for dive vacations and exotic locals, a $35 dollar a night hotel in central Florida is hardly exotic.
Yeah, I'm an idiot, unlike ol' whatisname -- Sheck Exley? -- the scuba cave diver and deep scuba diver extrordinaire... Oh, wait a minute. He's dead.
Now that is simply *$#%! up! Teir is no call for that. Would I, or any of us, disrespect you by poking fun at a fallen brother. No. The respect level has gone down.
In general, I appreciate all fo your comments, well except for the last one, and thank your for the great discussion. However, your techniques simply do not fit into our type of diving, just as ours do not fit yours.
Good Day.
James.