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Post by shackle on Apr 1, 2008 7:32:37 GMT -8
James, Do you mean I could have been banned from Fla. if I had been caught diving w/o a BC? Funny thing, I bought the horse collar to use at Sand Dog and never even got it wet. I'm sure glad I started this thread though; it has been fascinating reading. BTW I decided to forego the cartridge and installed a port plug.
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Post by nemrod on Apr 1, 2008 8:32:36 GMT -8
Steve, quite possibly, there were PadI Police under every bush and hiding in the bathrooms and behind rocks. I am telling, Karl is a good boy and even has his mask on backwards, what the hades is up with that Nem
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Post by duckbill on Apr 1, 2008 9:45:52 GMT -8
Oh, and Luis- I think you are right about the definition of decompression on a molecular level when partial pressures are considered. I think you and John were just using different definitions for "decompression". Simple semantics. Glad it got straightened out. I know that I am wasting my time, but I am glad you think that I am right. I would hate to have to tell all those researchers with their PHD and MD degree that they have a poor command of the English language. That's uncalled for, Luis. There's no need to be hostile. I wasn't. Now, I'm conceding that decompression can take place at different levels. Thankyou for reminding me of that. You aren't "wasting your time". I'm listening and learning. Maybe "semantics" was the wrong word. The definition of "decompression" is pretty simple. But, it was painfully obvious to this casual observer that the word was being applied in different ways by you and John in the course of your discussion. That is what I was pointing out. I was offering the term "outgassing" to describe what you call "decompression" at a microscopic level in order to avoid such confusion. It's really no big deal. Don't worry, be happy.
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Post by SeaRat on Apr 1, 2008 10:35:17 GMT -8
Ol Mossback,
To answer your question, I have not experienced any symptomology from these ascents, not even the buoyant ascents from the USS in Florida in 1967. I was on the Oregon coast diving with a buddy, and we were pulled over a rock from about 20 feet by a large wave. He experienced a subcutanious pneumothorax, which did not need treatment; I experienced no adverse effects.
Luis, I agree with your definitions, but still contend that you need some sort of pressure gradient to form bubbles. In order to get that in shallow depths, exposure time would need to be much greater than a few minutes at 20 feet. Yes, if enough nitrogen is absorbed, there can be a problem. But that would mean much more time be spent at the depth than I showed in my dive profile. The nitrogen doesn't immediately go into the system--it takes time to absorb nitrogen, especially at shallow depths when there is not much pressure gradient driving nitrogen into the bloodstream. Even the Suunto RBG system writeup gives many, many minutes at above 9 meters.
I would like to comment that anyone really concerned about DCS would at least think about having an on-board chamber available for these extended, decompression dives. Even the best tech divers make mistakes. I think I've discussed a few, but there are many more examples too. One very well-known researcher in the 1960s (name escapes me now) did a summer's research in a remote tropical area, and outfitted his boat with a chamber. He had to use it too, on his wife, I believe (I'll check tonight). I don't see the rationalizations of many for not having one available. I do know that there are liability concerns, and if that is the case then the laws need to be changed.
John
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Post by JES on Apr 1, 2008 14:46:38 GMT -8
Now, if your max depth is three feet like for our famous friend here, no worries. Don't have a clue as to if the CO2 is armed or not for this lovely old SeaTec, I know mine is not. Nem No CO2 cartridge in my SeaTec horsecollar. Just a threaded plug (from an LP port on a first stage) to fill the void after the CO2 cartridge was removed.
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Post by JES on Apr 1, 2008 14:52:12 GMT -8
James, Do you mean I could have been banned from Fla. if I had been caught diving w/o a BC?.... Maybe not Florida, but the Ginnie Springs Staff would have been only to glad to show you to the exit. BC's and pressure gauges are required equipment to dive there. Oh yes, and don't forget that your admission fee of $30.00 would not have been refunded.
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Post by SeaRat on Apr 5, 2008 18:29:53 GMT -8
I was a speaker at NAUI's IQ6 which was held October 4-6, 1974 in San Diego, California. I have a copy of the NAUI Proceedings of the Sixth International Conference on Underwater Education[/B], which had a number of speakers. I tonight went through this publication, and found the following article and reference, "Standardization in Cave Diving" by John R. Kessler, John states the following about equipment:
'Just thought I'd show you another opinion.
John
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Post by nemrod on Apr 5, 2008 19:23:03 GMT -8
Yep, that is what we discovered in the springs, the cartridge would snag and fire. In those days rather than plugging it with a port we just left the expended cartridge in there until it corroded beyond possibility of removal. We figured it was good to go then. While horsecollar BCs were used in the caves they were less than optimal and nobdoy was really pleased with them. The Dacor SeaChute pictured, really not vintage, was much better but still not as good as today's wings at promoting a horizontal or even feet up position. The lower envelope was power inflated or oral, the upper bag was oral via a small tube or CO2. Both however had full size dump valves thus allowing the use of the upper bag for reducndant bouyancy--orally inflated---the CO2 was not armed. This BC worked well for cave diving because the center of lift was under the belly promoting excellent horizontal trim and reducing silting. Nem
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