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Igge, the Canadians have some electric C-4 that trhe Navy tested . It won't do for them because of the current over the heart, and other such regulations, but it would work if you had a stationary deco - it needs scooter batteries to work. Scuba Pro has one also already to dive off the shelf that works on less battery and uses nicads. Ingemar Lundgren wrote: > > Dear mr aquafart, > A heating system if used to prolong the deco must of course bee redundant. > DONT TRY TO TEACH ME ANYTHING ABOUT COLD WATER DIVING. All my diving is cold > water diving so i know what i am doing. I am merely investigating the > possibility of building a proper heating system and i don't need advice from > experts like you who point out obvious things. It may bee the case that it > is impractical to use electrical heating and if i find that out i will not > use it. But i do think that it can bee worth looking in to atleast. > > Bill (aquadart) Bott wrote: > > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Sorry to give this more life, it has seen enough play already. > > However, as with so many things on the list, it refuses to die a > > graceful death. There is some misinformation, disinformation and > > misunderstanding that should be cleared up. If you are not > > interested in what I am about to write, please find the key labeled > > "delete" or "del", use it and go on with your life. > > > > First the misinformation / disinformation. As I have stated before I > > do NOT now nor have I EVER been employed at a dive shop. I am NOT an > > Instructor, Divemaster or "Dive Professional" of any sort. I chouse > > to patronize dive shops and receive training from those professionals > > that I feel have quality instruction and quality service. I do NOT > > represent anyone other that myself. My opinions are MINE!!! And > > although MAY be shared by others, I make no claim that any of my > > opinions are shared by any other individual. Further, although some > > people would like to control me, what I write and/or say, no one > > does!!! If my opinion(s) bother any individual or group, PLEASE, > > feel free to get over it!!! Or simply refer to the above > > instructions on the use of the delete key > > > > Now for a matter, that more directly relates to diving. The past > > thread on deep ice diving continues to go on. Despite my efforts to > > let it die there seems to still be some interest in breathing more > > life into it. A new thread has also developed regarding the use of > > supplemental heat for drysuits. I would like to share with you WHY I > > feel the those who propose this type of activity are DANGEROUS > > STROKES and exemplify what is wrong in sport / tech diving today. > > > > Under the best conditions Deep dives into the 300' range are taxing. > > Proper training, planing, conditioning and execution are all > > essential elements for conducting such a dive. Throw in additional > > complexities like overhead environments or cold bottom temps can > > further tax divers physical, emotional and intellectual resources. > > > > When conducting dives in deep cold water many factors come into dive > > planing. But thermal protection becomes a KEY element. The > > additional insulation needed to keep warm causes loss of mobility. > > The colder the water the more insulation, the less mobile the diver > > becomes. At some point, the loss of mobility becomes more that the > > diver can overcome and still operate safely. This is generally not a > > great problem in the Great Lakes during the summer because the > > surface temps rise rapidly through the spring and summer. The > > relatively short bottom times of the typical tech dive does not cause > > a major loss of core temperature in the diver. And relief from the > > cold (38 degrees) is found in the warmer surface temps, supporting > > the re-warming of a "chilled" diver. Argon use also helps to prevent > > the chilling. > > > > During an ice dive to any depth, the water is DAMN COLD. Just below > > the ice is a layer of water in liquid form that is 32-33 degrees. It > > is ready to freeze if given any encouragement for the cold above. > > Fortunately this layer of "cold" (all things are relative) is > > typically only a few inches in depth. Below that, the water is a > > balmy 36-38 degrees all the way to the bottom. During decompression, > > the diver has to contend with not only the cold bottom temp and the > > clod surface temps but also the fact that they are remaining > > relatively inactive. Loss of core temperature, in the diver, is not > > only likely but highly probable if the total dive time exceeds about > > 30 - 60 minutes. > > > > To over come this some divers use some form of supplemental heat. > > Chemical heat packs or Electric "britches" are two common forms of > > supplemental heat. And although they can provide a great deal of > > warmth and relief from the cold they must be looked at as another > > possible / probable failure point. And here is where I have a big > > problem with 300' + ice dives. > > > > In a properly configured rig, every "essential" piece of gear has a > > backup. But for deep decompression ice dives supplement heat becomes > > just such an essential piece of gear. During a shallow ice dive > > several years ago I was using a chemical heat pack for a little added > > comfort. And although I had used this method before successfully, I > > could not get the heat pack to activate during the dive as I had > > before. After surfacing I removed the heat pack and easily activated > > it. Good thing it was just for added comfort that day. > > > > The electric "chaps" are another method. And in theory is a good > > alternative. But like ALL electric devices, it is prone to fail. I > > forget who it was that said, during a presentation I attended, > > "Murphy LOVES to dive". The more I dive, the more I find this > > statement is true. If you leave anything to chance, chances are it > > won't work when you need it most! Further, in order to "insure" that > > the system will function properly when needed, redundant systems are > > required. Add to the list of gear needed, for any deep dive, extra > > battery pack(s) TWO sets of electric underwear and one if not TWO > > more holes in your drysuit. Beyond the gear added your rig you have > > added complexities. Managing the gear, moving the gear and switching > > to a backup system if (when) the primary system fails. > > > > When you make the decision you are going to do a deep ice dive with > > the needed deco, you must recognize that supplemental heat is no > > longer a luxury, it is necessity! How you deal with all the extra > > gear and how you handle the problems that ARE going to occur WILL be > > the difference between a fun dive and DEATH. To take this one step > > further, how the addition to the gear affects the original > > configuration becomes a concern. > > > > Again, proper dive planing mandates that the diver can abort a dive > > and return safely at any point in the dive. But when supplemental > > heat become essential for the success of the dive you have an > > accident waiting to happen. Even if multiple back ups are used there > > still flaws in the system. Not only in how to deal with a broken > > wire inside the suit. But how do you deal with a flooded suit? One > > second your warm and dry, next second Willie the One Eyed Wonder Worm > > took the string and left town! If you manage to survive it will be > > weeks before you can pee standing up again. > > > > The problem of a suit flood is NOT dire if the surface temps are > > warmer, as they are in the summer months. Relief from the biting > > cold is only a short distance away in the warmer surface waters. But > > with constant water temperatures of 36-38 degrees or less from bottom > > to last stop at 10', there is no relief. Only continued loss of core > > temperature. Further complicating matters by adding more gear is not > > the answer either. Every piece of extra gear only takes away from > > the safety of the dive. It DOES NOT enhance it!!! Only a fool would > > spend more money for less safety. Only a DANGEROUS STROKE would > > suggest that others do the same > > > > I take a lot of heat there because of my firm stand against what I > > see as stupidity. But we must all realize that if we don't start to > > think things through, use our heads and make sound ration decisions > > about our diving habits we will no longer be able to peruse our > > sport. It is some times hard to make every point as clear as I have > > tried to make this one. Some times, I resort to what I call the > > "Bitch Slap" method to get the attention of others. However, I > > assure you that every reply I post is thought out as carefully as > > this one was. I also assure you that I will continue with this > > approach until all those afflicted with Cerebralanalitus are cured or > > at least in remission. > > > > To all those following blindly, > > > > Stop!!! Ask yourself this one question. Am I following the lead of > > someone who knows, someone who thinks they know or someone so > > clueless that they will kill me with out even realizing a problem > > existed? If you can't be certain that they KNOW, go home and read a > > book. Don't let someone else convince you that stupid is okay > > because they are the "Instructor". If it sounds dangerous, you are > > either not ready to do it or shouldn't be doing it at all. It is > > that simple. > > > > Be safe! Be smart! And have a Happy Holiday everyone > > > > > > > > -----BEGIN PGP SIGNATURE----- > > Version: PGP for Personal Privacy 5.0 > > Charset: noconv > > > > iQA/AwUBNJy8C/PdqRXLjbJGEQKSAACfaaXCScHDjBi3eG6pBiUKc5JBdYAAoO0n > > Bk+r3ybOPYRH3zGbHXy3Bhgy > > =qoV+ > > -----END PGP SIGNATURE----- > > > > Bill (aquadart) Bott > > -- > > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. > > -- > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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