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Scuba Forum / General / August 2007Dive tables
My younger brother just got certified around the Dallas (Garland,actually) area by a SDI agency. In talking with him I learned that they never mention dive tables. He said they never came up adn he never heard of them. Does anybody know if that is the norm now - no mention or teaching the dive tables? What do you do if your computer (if you use one) craps out, what about surface intervals? > My younger brother just got certified around the Dallas > (Garland,actually) area by a SDI agency. In talking with him I learned [quoted text clipped - 4 lines] > dive tables? What do you do if your computer (if you use one) craps > out, what about surface intervals? SDI teaches the use of a dive computer, tables are covered in an appendix. I would hope that the instructor touched on the use of tables and the benefits of a backup computer. John > SDI teaches the use of a dive computer, tables are covered in an appendix. > > I would hope that the instructor touched on the use of tables and the > benefits of a backup computer. Hmmm... Sounds like they are going with the approach that if you don't teach the tables, you can sell 2 computers to each diver... Might just work... <grin> > My younger brother just got certified around the Dallas > (Garland,actually) area by a SDI agency. In talking with him I learned [quoted text clipped - 4 lines] > dive tables? What do you do if your computer (if you use one) craps > out, what about surface intervals? Well, Kaitlyn got certified not too long ago (a couple months or so) and SSI is still using tables... Of course they try to sell the students dive computers, but the hard sell is not as bad as some shops... > My younger brother just got certified around the Dallas (Garland,actually) > area by a SDI agency. In talking with him I learned that they never > mention dive tables. He said they never came up adn he never heard of > them. > Does anybody know if that is the norm now - no mention or teaching the > dive tables? What do you do if your computer (if you use one) craps out, > what about surface intervals? That's been reported from SDI for some time now. They are, generally speaking, the least respected agency among the more experienced segments of the dive community. As for what to do if your computer craps out, you do exactly what every computer manufacturer and every entry level certification agency recommends, you sit out a minimum of 24 hours before making your next dive. Surface intervals are no particular problem, you do them until your computer shows adequate bottom time for the next dive you plan to do. Personally, I think it's a big mistake not to teach tables. While it is possible, and even likely that many divers will depend on a computer for all of their post training dvies, I still think they are one of, if not the best channel to learning about decompression. Obviously, SDI doesn't agree. I suspect it won't be long before other agencies follow their lead. Lee >> My younger brother just got certified around the Dallas (Garland,actually) >> area by a SDI agency. In talking with him I learned that they never [quoted text clipped - 20 lines] > >Lee If you don't understand the tables, using a computer is a great way to eventually get into trouble. Hell, even PADI teaches tables (and THE WHEEL) and we all know that PADI shops really, really, really want to sell you a computer.  Signaturedillon Broadway Photo sucks. Ask me why. >>> My younger brother just got certified around the Dallas >>> (Garland,actually) [quoted text clipped - 32 lines] > WHEEL) and we all know that PADI shops really, really, really want to > sell you a computer. PADI teaches tables but also computers. While many divers are now using computers, knowing how to use the dive tables makes a lot of sense and explains the theories involved. My first Naui instructor didn't trust computers and doesn't use them. He said he's taken several computers down with him and they all give him different readings. If my computer crapped out I'd probably quit for 24hrs while it was being repaired. Anyway, IMHO I believe since most novice divers don't dive complicated dive plans, they should all be using tables to start with -- maybe with a computer for a backup. Never, ever using tables is like learning how to fly a plane while never knowing what keeps it up. >>>> My younger brother just got certified around the Dallas >>>> (Garland,actually) [quoted text clipped - 41 lines] > computer for a backup. Never, ever using tables is like learning how to fly > a plane while never knowing what keeps it up. Dive planning and the physics are still covered, the difference is they use their computers to plan and execute their open water cert dives instead of tables. John "Sheldon" <sheldon@XXXXXXXXsopris.net> pounded away at his keyboard resulting in: :PADI teaches tables but also computers. While many divers are now using :computers, knowing how to use the dive tables makes a lot of sense and :explains the theories involved. What theories are those? Dan Bracuk Never use a big word when a diminutive one will do. > "Sheldon" <sheldon@XXXXXXXXsopris.net> pounded away at his keyboard > resulting in: [quoted text clipped - 4 lines] > > What theories are those? Maybe not theories, but the fact that the longer you stay down, or the deeper you go, the more nitrogen is being absorbed into your bloodstream and the longer you have to rest at the surface. While a computer will hand you the information you need, having to use a table just confirms what the computer is doing. For example. 2+2=4. I can punch the numbers into a calculator and you can see the answer. But, as a novice mathematician, showing you two apples and then adding two apples to make four apples visually explains the answer the calculator is giving you. Ever go to the store and buy something for $3.26? You hand the clerk a $5 bill and he punches all of this into the cash register's computer. Reach in your pocket and hand the clerk 26 cents after the fact and most of them don't understand the concept of change enough to do the math and simply take the 26 cents and hand you $2. Many of them, and I mean many, never had to make change without a computer. So, they back out the sale and start all over again. I'm not saying we shouldn't use dive computers, or computerized cash registers for that matter, but it helps to understand what's behind the answers the computer is giving you, and it's not exactly rocket science. > I'm not saying we shouldn't use dive computers, or computerized cash > registers for that matter, but it helps to understand what's behind the > answers the computer is giving you, and it's not exactly rocket science. The computer is giving you information attenuated by lawyers and insurance companies, designed to make sales at the LDS. My Hewlett Packard calculator has more computing power than was available to the guys that put the LEM on the moon. Even at that, Niel Armstrong had to land it manually. There endeth the lesson. >> I'm not saying we shouldn't use dive computers, or computerized cash >> registers for that matter, but it helps to understand what's behind the [quoted text clipped - 10 lines] > > There endeth the lesson. You got my point. If you understand what's behind the computer's calculations, not how the computer works, you can probably get yourself out of a jam if needbe. >> I'm not saying we shouldn't use dive computers, or computerized cash >> registers for that matter, but it helps to understand what's behind the [quoted text clipped - 5 lines] > My Hewlett Packard calculator has more computing power than was available to > the guys that put the LEM on the moon. Why, how much memory does it have? Is it backed up by a remote computer that does failsafe calculations? > Even at that, Niel Armstrong had to land it manually. > > There endeth the lesson. The bad lesson He didn't have to land it manually, he was told by Earth control to ignore a warning light. Big deal. http://www.abc.net.au/science/moon/computer.htm Amazing how history is rewritten to help a weak arguement. >>> I'm not saying we shouldn't use dive computers, or computerized cash >>> registers for that matter, but it helps to understand what's behind the [quoted text clipped - 23 lines] > > Amazing how history is rewritten to help a weak arguement. Same thing happened to me. Magilla said, "Ignore that warning light!" No problem. esg > The bad lesson "Their system worked, but almost caused the first moon landing to be aborted in the final minutes before the touchdown." > He didn't have to land it manually, he was told by Earth control to > ignore a warning light. Big deal. > > http://www.abc.net.au/science/moon/computer.htm > > Amazing how history is rewritten to help a weak arguement. You are full of sh.t. http://www.nasm.si.edu/collections/imagery/apollo/AS11/a11landsite.htm "For the first lunar landing, Mare Tranquilitatis was the site chosen because it is a relatively smooth and level area. It does, however, have a high density of craters and in the last seconds before landing, the LM had to be manually piloted by Neil Armstrong to avoid a sharp-rimmed ray crater measuring some 180 meters across and 30 meters deep known as West. The LM landed safely some 6 km from the originally intended landing site." > Ever go to the store and buy something for $3.26? You hand the clerk a $5 > bill and he punches all of this into the cash register's computer. Reach in [quoted text clipped - 3 lines] > make change without a computer. So, they back out the sale and start all > over again. And all these dumb clerks had more times tables and adding apples and oranges then you ever had dive tables. It's required education to have years of mathematics instruction, sometimes as advanced as pre- algebra. Yet they still can't add or subtract without calculators. That's exactly SDI's point. What's the use of tables if the dumb divers are going to forget them and rely on computers for their diving anyway? Would you rather have the dummy who makes mistakes giving change try to plan out his diving without error? Good grief. >> Ever go to the store and buy something for $3.26? You hand the clerk a >> $5 [quoted text clipped - 16 lines] > anyway? Would you rather have the dummy who makes mistakes giving > change try to plan out his diving without error? Good grief. No, but I'd rather have the guy who knows how to count out change back to the customer when the computer breaks down working for me than the other guy. I think most people who use dive computers rely on them completely, but if you merely understand dive tables and how they relate to dive computers you can use your brain, and watch, as a backup. Whether you use tables or a computer it's not a bad idea to have a dive plan and a rough idea of the plan's limits. > I think most people who use dive computers rely on them completely, but if > you merely understand dive tables and how they relate to dive computers you > can use your brain, and watch, as a backup. No you can't, not for repetitive multilevel profiles. No brain is that good, not even mine. > Whether you use tables or a computer it's not a bad idea to have a dive plan > and a rough idea of the plan's limits. That negates much of the reason for having a computer in the first place. If you already have a plan and plan to stick to the plan, why do you need a computer? > That negates much of the reason for having a computer in the first > place. If you already have a plan and plan to stick to the plan, why > do you need a computer? Depends on the plan - my plan, especially when I pay for the dives, is to stay down as bloody long as I can. :) V. "Sheldon" <sheldon@XXXXXXXXsopris.net> pounded away at his keyboard resulting in: :Maybe not theories, but the fact that the longer you stay down, or the :deeper you go, the more nitrogen is being absorbed into your bloodstream and [quoted text clipped - 18 lines] :registers for that matter, but it helps to understand what's behind the :answers the computer is giving you, and it's not exactly rocket science. My analogy is different. The objective is to analyse some data (depth, time, interval) to get some information. Dive tables enable you to do it much like a slide rule enables you to do guzintas. Computers enable you to do it much like a calculator enables you to do guzintas. The amount of necessary background theory is the same for both. Dan Bracuk Never use a big word when a diminutive one will do. > "Sheldon" <sheldon@XXXXXXXXsopris.net> pounded away at his keyboard > resulting in: [quoted text clipped - 4 lines] > > What theories are those? to name a view: - you get bubbles only if you dive below 30 m - there are no sharks below 30 m ;-) Matthias > My younger brother just got certified around the Dallas > (Garland,actually) area by a SDI agency. In talking with him I learned [quoted text clipped - 4 lines] > dive tables? What do you do if your computer (if you use one) craps > out, what about surface intervals? This has been the SDI way for the past several years. NAUI and YMCA standards still do and I hope always will require tables to be taught. YMCA standards are the most stringent of these agencies and PADI. I will teach a YMCA OW course over NAUI, and I have never taught an SDI OW. I am not a PADI instructor, so cannot comment on their standards past slight knowledge. * Timely discussion. My computer went titsup Saturday, yesterday I cruised the web looking for a basic nitrox hockey puck, discovered (1) There's no such thing as a basic computer any more, and (2) they are ridiculously expensive. I've decided to go back to tables and a $17 Casio watch. esg > My computer went titsup Saturday, yesterday I cruised the web looking > for a basic nitrox hockey puck, discovered (1) There's no such thing as > a basic computer any more, and (2) they are ridiculously expensive. A Mosquito is what, $250? That's quite cheap... V. >>My computer went titsup Saturday, yesterday I cruised the web looking >>for a basic nitrox hockey puck, discovered (1) There's no such thing as [quoted text clipped - 3 lines] > > V. $340, then ya got to grind off the wrist mounts so ya can carry it where it belongs. $340 for something that is no more high tech than a waterproof TickleMeElmo insults my intelligence. esg > $340, then ya got to grind off the wrist mounts so ya can carry it where > it belongs. > > $340 for something that is no more high tech than a waterproof > TickleMeElmo insults my intelligence. http://www.leisurepro.com/Prod/CategoryID_1985/Context_ 954/Sort_Price/DescSort_0/Filter_3%3d2003/OCNV18W.html?Hit=1 Oceanic "Veo 180" Air/Nitrox Wrist Dive Computer - $199.95, free shipping & handling. >>$340, then ya got to grind off the wrist mounts so ya can carry it where >>it belongs. [quoted text clipped - 8 lines] > Oceanic "Veo 180" Air/Nitrox Wrist Dive Computer - $199.95, free shipping & > handling. Wrist. Worse than useless. esg >>>$340, then ya got to grind off the wrist mounts so ya can carry it where >>>it belongs. [quoted text clipped - 11 lines] > > esg Are we now putting out lives in the hands of the lowest bidder? I agree to a point. The problem is you won't die if a TickleMeElmo doll goes south. Hence, the high prices on dive computers regardless of how technically simple they really are. > Are we now putting out lives in the hands of the lowest bidder? I agree to > a point. The problem is you won't die if a TickleMeElmo doll goes south. > Hence, the high prices on dive computers regardless of how technically > simple they really are. You also don't die if you know what the f.ck you are doing and have a Timex or Casio. Counting on overpriced computers that fail is just embracing ignorance of simple facts. > You also don't die if you know what the f.ck you are doing and have a > Timex > or Casio. > Counting on overpriced computers that fail is just embracing ignorance of > simple facts. Timex and Casio fail too. In fact, I've had several times more Timex failures than dive computer failures over the years. For some of us, using a dive computer is embracing laziness, or even versatility rather than ignorance. With a computer, I have to do very little planning in advance. Other than having an idea of how deep, for how long I can dive given my previous dives, I don't have to do any planning at the beginning of the dive or worry about how multi level my profile is. Of course, that's enough to ensure you get out of the current dive safely even if your computer fails, but it plays hell with any additional dives you plan on doing the same day. I'd love to see someone without a computer try to figure out how to do one of our annual spearfishing trips, where we do 6 dives one day, 7 dives the next, and three or four on the way back to the docks, all in water 60 - 100 feet deep, managed only by when and where the next fish or lobster appears and by the time and depth information on our computers. Lee "Scott" <pugetsounddiver@gmail.com> pounded away at his keyboard resulting in: :You also don't die if you know what the f.ck you are doing and have a Timex :or Casio. : :Counting on overpriced computers that fail is just embracing ignorance of :simple facts. Computers don't require one to stop thinking. On the other hand, they enable the diver to enjoy the dive now that he doesn't have to continuously track depth and time. That's why smart divers use them. Dan Bracuk Never use a big word when a diminutive one will do. > Computers don't require one to stop thinking. On the other hand, they > enable the diver to enjoy the dive now that he doesn't have to > continuously track depth and time. That's why smart divers use them. Guess that's 2 people who think I'm not smart....... "\"Magilla\"" <cavey_curtis@$$ yahoo.com> pounded away at his keyboard resulting in: : Guess that's 2 people who think I'm not smart....... Always room for improvement. Doesn't GUE teach you to use the most appropriate equipment for the dive at hand? Dan Bracuk Never use a big word when a diminutive one will do. > : Guess that's 2 people who think I'm not smart....... > > Always room for improvement. Doesn't GUE teach you to use the most > appropriate equipment for the dive at hand? Not sure at what point they wean one from them. My original cert was in the last century, by recert time I had already been mentored past using one. Most I cave dive with do not use computers, some that do use them do so for logging rather than planning. I very comfortably plan and execute dives beyond recreational limits (timewise, depthwise & gaswise) using just a bottom timer, haven't used a dive computer in about 5 years or so, even before then I frequently just bent an air computer into gauge mode. When I made my last choice, it was between a Uwatec BT and a Vyper, to use in gauge mode, made my decision based on cost, lack of need to download profile & lack of need to use the computer function, so the Uwatec BT won. For me, using a dive computer would be a giant step BACKWARDS. Curtis > Not sure at what point they wean one from them. My original cert was in > the last century, by recert time I had already been mentored past using > one. Most I cave dive with do not use computers, some that do use them do > so for logging rather than planning. Here we go again. Cave divers don't use them because they don't work for the kind of diving they do. They are not the right tool for that job, although my multigas Nitek He comes close. > I very comfortably plan and execute dives beyond recreational limits > (timewise, depthwise & gaswise) using just a bottom timer, haven't used a [quoted text clipped - 3 lines] > based on cost, lack of need to download profile & lack of need to use the > computer function, so the Uwatec BT won. Works just fine until you do a series of dives you can't, or prefer not to, plan in advance. My Tortugas spearfishing trips are a great example. At the beginning of each dive, at best, I know about how deep the site is. I don't know how deep I'll go, how long I'll stay how deep, or how many times I'll be up and down during the dive. I have an idea about the maximum duration of the dive, but not how long it will actually last . . . times 7 in one day. > For me, using a dive computer would be a giant step BACKWARDS. Depends on how and when you use it. For recreational diving, it's neither a step backwards or forwards on dives you actually plan in advance. Lee > Here we go again. Cave divers don't use them because they don't work for > the kind of diving they do. They are not the right tool for that job, > although my multigas Nitek He comes close. They are not the right tool for any dives I do, and you know my "technical" and "transitional" profiles are not a majority. They are a crutch, even you admit that they are, through plecibic terms. Unnecisary for most recreational diving, except to the crowd who is perhaps undertrained. Maybe a convenience, but not a necesity. Dan Bracuk just completed 27 very nice recreational dives that realistically would require no computer, no tables, not even a watch except to know when to return to the boat. A glance at a table will confirm this. Even the 120 foot dive John and I did, followed by one of those shallow reefers, needed no real calculating. The typical set of reef dives on the tourist boats are no-brainers if 32% is used. >> I very comfortably plan and execute dives beyond recreational limits >> (timewise, depthwise & gaswise) using just a bottom timer, haven't used a [quoted text clipped - 3 lines] >> based on cost, lack of need to download profile & lack of need to use the >> computer function, so the Uwatec BT won. > Works just fine until you do a series of dives you can't, or prefer not > to, plan in advance. My Tortugas spearfishing trips are a great example. [quoted text clipped - 3 lines] > maximum duration of the dive, but not how long it will actually last . . . > times 7 in one day. Brings up the question of if it's not a better example of a computer telling you it's ok to do diving that in reality is not the wisest, if according to you they cannot be matched. >> For me, using a dive computer would be a giant step BACKWARDS. > > Depends on how and when you use it. For recreational diving, it's neither > a step backwards or forwards on dives you actually plan in advance. For me, it's no doubt a big step backwards, depending on nothing but the truth in its purest form. Curtis > Even the 120 foot dive John and I did, followed by one of those shallow > reefers, needed no real calculating. > > The typical set of reef dives on the tourist boats are no-brainers if > 32% is used. You're right about that. But what about a typical liveaboard schedule where any or all of the dives might be to 100'+ maximum depth, four or five of those per day, each dive lasting an hour? There's no way you could do those in your head without seriously limiting your range compared to the computer diver. Those of us who do these sorts of trips want to maximize their bottom time and flexibility. Your approach is not the best for all types of diving. > > Even the 120 foot dive John and I did, followed by one of those shallow > > reefers, needed no real calculating. [quoted text clipped - 11 lines] > time and flexibility. Your approach is not the best for all types of > diving. That's probably why all of the liveaboards I've been on *required* computers. gc > They are not the right tool for any dives I do, and you know my > "technical" and "transitional" profiles are not a majority. They are the right tools for the dives I do, and you know my "technical" and "transitional" profiles are not a majority either. The point is not whether they are the right tools for the dives you do, but whether they are the right tools for the diving anyone may do. They clearly are. > They are a crutch, even you admit that they are, through plecibic terms. Not exactly. They allow a different approach to diving, one that does not require significant pre planning. That's far more than simply a crutch. Technical diving aside, diving with a computer is more versatile and more adaptable than diving without one. I'll remind you that, on the dives we do together, I accommodate your style and plan rather than the other way around. I'll also remind you that you know that some of those who, historically, were most vocal in claiming that they never used a computer for anything other than recorder, were lying. > Unnecessary for most recreational diving, except to the crowd who is > perhaps undertrained. Maybe a convenience, but not a necessity. With emphasis on the word "most." As for being undertrained, that's a tough thing to rely on. It's very hard to define without first answering "undertrained for what?" How are your closed circuit rebreather skills? Greg knows how to use one. Is he undertrained, or are you? >> Works just fine until you do a series of dives you can't, or prefer not >> to, plan in advance. My Tortugas spearfishing trips are a great example. [quoted text clipped - 3 lines] >> maximum duration of the dive, but not how long it will actually last . . >> . times 7 in one day. > Brings up the question of if it's not a better example of a computer > telling you it's ok to do diving that in reality is not the wisest, if > according to you they cannot be matched. So, the fact that they can't be done safely without a computer makes them less than wise? One could say the same thing about diving people you know do that does not comply with any officially recognized dive tables or computers. They, and we, have shown the ability to do them and survive. We have been doing it longer, have more examples, in more environments, for more times and more total hours, than they do. >> Depends on how and when you use it. For recreational diving, it's neither >> a step backwards or forwards on dives you actually plan in advance. > For me, it's no doubt a big step backwards, depending on nothing but the > truth in its purest form. Saying it more than once does not make it any truer. Any time you'd like to try a series like I do every year, without a computer, let me know. Be prepared to pay the cost of having a chamber on site. I'd no more like you to learn the limits of computerless diving the hard way than I would like to learn the limits of diving with one the same way. Lee >> They are not the right tool for any dives I do, and you know my >> "technical" and "transitional" profiles are not a majority. [quoted text clipped - 5 lines] > they are the right tools for the dives you do, but whether they are the > right tools for the diving anyone may do. They clearly are. Not at all clearly to me. As I have stated, quite a number of divers could do well without them. Both ends of the spectrum, the newbies and the "real" advanced, do not need them at all. The middle group really doesn't either, they just want them, (and in the process get copied by newbies trying to get "there" quickly). Their choice, but to the claims of full superiority, bullshit. Convenient, OK, lazy way, OK, easier, maybe to the lazy, but be honest. I personally think that the dive shop who insisted I use one to do a single 100 FSW dive, preceeded by two 25 FSWs and a long SI, then followed by another 25 FSW one was the clueless one. Wouldn't even refer to a table for that one, just my table based in-head calculations. >> They are a crutch, even you admit that they are, through plecibic terms. > > Not exactly. They allow a different approach to diving, one that does not > require significant pre planning. That's far more than simply a crutch. OK, an electric wheelchair then. > Technical diving aside, diving with a computer is more versatile and more > adaptable than diving without one. I'll remind you that, on the dives we > do > together, I accommodate your style and plan rather than the other way > around. Not applicable to my comments on this thread, for many reasons. Your main "accomodation" is tighter "buddy diving". > I'll also remind you that you know that some of those who, historically, > were most vocal in claiming that they never used a computer for anything > other than recorder, were lying. Since my only recollection of this is basically your statements, you're merely reminding me of your version. I have no real recollections of such history either way, and I damn sure have no recollection of public statements by anyone I know that were lies on this issue. As I've tried to explain before, the "boisterous years" predated my involvement for the most part. Although I know a few well known divers, whom I cannot possibly nor would I be arrogant enough to speak for, most of my dive friends would be unknown to you or most here, except maybe to Al Wells. As to Dan's comments, I actually was diving with NACD, CDS & GUE divers when I started using a BT, so it wasn't an agency as much as a dive philosophy. Yeah, I learned it when doing technical, but found it preferable for my recreational diving also. I personally never claimed I never used one, I did indeed use an air computer as a newbie, and learned how to somewhat use it as a guage early in the game before it got replaced. You witnessed this stage, not sure you understood how I was using it. I bought an overpriced toy and was convinced I needed it, was stuck with it during a period of lesser dive funding. Same thing the industry in general does with most newbies, with y'all's full endorsements. >> Unnecessary for most recreational diving, except to the crowd who is >> perhaps undertrained. Maybe a convenience, but not a necessity. > With emphasis on the word "most." As for being undertrained, that's a > tough > thing to rely on. It's very hard to define without first answering > "undertrained for what?" Well, since the thread was started talking about omiting teaching tables to OW divers...... > How are your closed circuit rebreather skills? Greg > knows how to use one. Is he undertrained, or are you? Red Herring. Not to mention as unimpressive as a solo certification. >> Brings up the question of if it's not a better example of a computer >> telling you it's ok to do diving that in reality is not the wisest, if >> according to you they cannot be matched. > So, the fact that they can't be done safely without a computer makes them > less than wise? More like the fact that you're "implying" they cannot be done without a computer implies that you may be doing profiles not really advisable, with or without a computer. Or, you're overstating what is done on the profiles, which I interpret as multi-level Nitrox depth multiple dives with no dive plan and possible sawtoothing and bouncing. Something you challenge me on for some reason when you know I do plan my dives, and would limit myself because of physics rather than computer generated interpolation. Not to mention possible violations of gas management and buddy management to my standards I caught hints of in past descriptions. In a dive situation a far cry from the typical tourist dive. To somehow equate that with tech divers using proven deco programs to plan their deco profiles is ignorant. To follow my self-imposed rules of engagement, time for me to withdraw, hope you'll understand without taking advantage of my choices. Curtis >> They are the right tools for the dives I do, and you know my "technical" >> and [quoted text clipped - 4 lines] > > Not at all clearly to me. None is so blind as he who will not see. > As I have stated, quite a number of divers could do well without them. Quite a few divers could do without long hoses, manifolded twins, steel or aluminum plates, drysuits, wetsuits, the list goes on. Your statement is true but irelevant. > Both ends of the spectrum, the newbies and the "real" advanced, do not > need them at all. Half right at least. With the wide variety of dive operators that will take entry level divers on advanced levels dives, many newbies probably do need them. That's a different problem, but a valid consideration. One has to deal with life as it is, not as it should be. > The middle group really doesn't either, they just want them, (and in the > process get copied by newbies trying to get "there" quickly). Their > choice, but to the claims of full superiority, bullshit. Convenient, OK, > lazy way, OK, easier, maybe to the lazy, but be honest. The offer stands. Do what I do every year, without a computer and you will have made your point. Otherwise, you're just as wrong as those that claim computers are necessary for all diving. > I personally think that the dive shop who insisted I use one to do a > single 100 FSW dive, preceeded by two 25 FSWs and a long SI, then followed > by another 25 FSW one was the clueless one. Wouldn't even refer to a > table for that one, just my table based in-head calculations. So do I. This statement is also irelevant. >> Not exactly. They allow a different approach to diving, one that does not >> require significant pre planning. That's far more than simply a crutch. >> Technical diving aside, diving with a computer is more versatile and more >> adaptable than diving without one. I'll remind you that, on the dives we >> do together, I accommodate your style and plan rather than the other way >> around. > Not applicable to my comments on this thread, for many reasons. Of course it is. > Your main "accomodation" is tighter "buddy diving". Not at all. I did accomodate you with tighter buddy diving, but that was not my main accomodation. My main one was following your profile. >> I'll also remind you that you know that some of those who, historically, >> were most vocal in claiming that they never used a computer for anything >> other than recorder, were lying. > > Since my only recollection of this is basically your statements, you're > merely reminding me of your version. Not only unwilling to see, also unable to remember. Convenient. > You witnessed this stage, not sure you understood how I was using it. I recall that you spent an entire dive breathing nitrox as though it was air and spent a substantial portion of the dive well above me because your air computer said you were out of no deco time. That was a long time ago and a pretty good example of a dive where your current methods would have been better than those you used at the time. > I bought an overpriced toy and was convinced I needed it, was stuck with > it during a period of lesser dive funding. Same thing the industry in > general does with most newbies, with y'all's full endorsements. You don't need it because you don't dive in a way that requires it. Others do. We don't endorse the industry's sales pitch, we recommend that those that are going to purchase expensive equipment anyway, choose equipment that will be most versitile because, as beginners, they don't know what they'll end up doing and because replacing a piece of equipment later is more expensive than spending a few bucks more for it in the beginning. >> With emphasis on the word "most." As for being undertrained, that's a >> tough >> thing to rely on. It's very hard to define without first answering >> "undertrained for what?" > Well, since the thread was started talking about omiting teaching tables > to OW divers...... Yes it did, but it morphed from there. The agency responsible does not believe they are undertrained for the diving they will be doing. I'm not sure they are either, even though I think the odds are good that someone that learns the tables will have a better grasp of decompression issues. You don't believe you are undertrained for the diving you are doing. You may both be correct, but neither of you is speaking for the diving that others are doing. >> How are your closed circuit rebreather skills? Greg knows how to use one. >> Is he undertrained, or are you? > Red Herring. Makes the point though, doesn't it? You have to be more specific if you're going to define undertrained. > Not to mention as unimpressive as a solo certification. What's more or less impressive about a solo certification than any other of hundreds of specialty certifications? > More like the fact that you're "implying" they cannot be done without a > computer implies that you may be doing profiles not really advisable, with > or without a computer. Apply the same thing to your own diving. Your diving can't be done as safely without specialized tools either. Are we, therefore, to conclude that your profiles are not really advisable either? > Or, you're overstating what is done on the profiles, which I interpret as > multi-level Nitrox depth multiple dives with no dive plan and possible > sawtoothing and bouncing. Call it by whatever name you like, but until you can figure out how to do it safely without a dive computer, you're belief that a computer is not the right tool for anyone is unsupported. > Something you challenge me on for some reason when you know I do plan my > dives, and would limit myself because of physics rather than computer > generated interpolation. Because your statements regarding computers continue to ignore exactly that kind of dive. The only reason I keep challanging you on that point is because that's exactly the kind of diving computers are necessary for. Besides, every dive you've done with potential decompression issues, has been done because of computer generated interpolation. Just because the computers that cut your tables will not survive immersion does not make them any less a computer. > Not to mention possible violations of gas management and buddy management > to my standards I caught hints of in past descriptions. Different issues. Management of any aspect of diving is a personal thing. Computers are only tools, sometimes tools that allow a diver to do things he could not practically do otherwise, just like some of the tools you use, but they don't manage the dive, any more than the tools you use manage yours. Only the diver can do that. > To somehow equate that with tech divers using proven deco programs to plan > their deco profiles is ignorant. Then why do you continue to do it? You keep talking about how a computer is not necessary for the diving you do and ignoring the fact that the only reason that's true is because you're not doing the kind of diving that requires one. Your statement is no more or less ignorant than the reverse. > To follow my self-imposed rules of engagement, time for me to withdraw, > hope you'll understand without taking advantage of my choices. Sure, as long as I get the last word. > > Not at all clearly to me. > None is so blind as he who will not see. Bingo. Look in the mirror. Lee, I love you man, but you are beating a dead horse and trying to justify a wrong mindset. Computers don't "allow" you to do anything. Let me ask you this (obviously hypothetical); After each of 6 or 7 dives a day on your dream vacation live-aboard, what would your tissue load be if you breathed 50% or O2 for 5 or ten minutes, with the proper air breaks, on your SI? How would your computer account for that or "allow" you to dive after? SURDO2 Just another method, another mindset, and one that has literally hundreds of thousands of man hours behind it that aren't attenuated by ignorance, lawyers and insurance companies. Step off man. Computers don't keep anyone safe, or "allow" any diver to do anything, they are a crutch, and an expensive one. You are good enough at math that you could spend a few of the hours you spend here running profiles through GAP (best on the market, IMHO, and 1/10th to 1/100th the cost of a computer) to understand a very basic issue. Bottom timer, understanding, and the Homo Sapiens Mk1 Mod0 work just fine. And I am here to tell you, as is Curtis. > Lee, I love you man, but you are beating a dead horse and trying to > justify > a wrong mindset. You too are welcome to try to match my 6 and 7 dive days at depths from 60 to 80 feet, with no idea at the beginning of any dive how long you'll be how deep, without a computer. > After each of 6 or 7 dives a day on your dream vacation live-aboard, what > would your tissue load be if you breathed 50% or O2 for 5 or ten minutes, > with the proper air breaks, on your SI? 50% isn't available. Choices are 21% and 32%. > How would your computer account for that or "allow" you to dive after? Depends on which computer I'm using. Both my NiTek Duo, which allows me to switch between two versions of nitrox, and my NiTek He, which allows me to switch between 7 different flavors of trimix, would handle it just fine. Since only air and nitrox are available on the trips, my Oceanic or Genisis computers are good enough. > You are good enough at math that you could spend a few of the hours you > spend here running profiles through GAP (best on the market, IMHO, and > 1/10th to 1/100th the cost of a computer) to understand a very basic > issue. I'm more likely to use DecoPlanner because I'm familiar with it. The point is, though, you have to know what the dive is going to be to plan it. I've stated (admitted) more than once, that a dive you can plan, can be done safely without a computer. Curtis does them all the time and, for those dives, he's right. He doesn't need a computer and, because when we dive together, I dive his plan with him, neither do I. What the computer does is cut you free from that need to plan in advance. > Bottom timer, understanding, and the Homo Sapiens Mk1 Mod0 work just fine. Only when you spend the majority of your dive on the bottom. Neither you, nor Curtis can plan a dive in advance if you don't know what the dive is going to be like in advance. You don't know where or when the fish will show up, where or when the lobster will show up, or how long or how you will stalk either until the opportunity presents itself. So I spend much of my time in mid water to conserve time at depth for when I need to be at depth. Hell, it wasn't all that many years ago that every agency there is would have sworn my "planned" profile would kill me after only one dive, let alone 13 in two days. On my trips, I run on the edge of my no deco and O2 limits from somewhere near the end of dive two, through the end of dive 16 or 17, two and a half days later. I adjust depth during each dive, and the gas for some dives (I do one or two air dives around noon of the second day to keep my computer's CNS clock happy) so that I don't significantly cross either line during the trip. You just can't dive that much, with that kind of flexibility, without a computer. Curtis has made several correct statements on this subject. He was right when he said that most dives could be done without one. He was right when he said that all the diving he currently does, could be done without one. He was wrong when he said that they were not the right tool for any diving that could be done. Lee >>Lee, I love you man, but you are beating a dead horse and trying to >>justify [quoted text clipped - 3 lines] > to 80 feet, with no idea at the beginning of any dive how long you'll be how > deep, without a computer. OK. Let me be the third. Of the dives you mention, which ones would have not fitted in here: Dive as you please, then, after you decided to surface, do 2 minutes at 9m(30ft), 5 minutes at 6m(20ft), 13 minutes at 3m(10ft) I bet this would leave you with a) sufficient bottom time b)sufficient gas In case a dive plan (as you sugest, a diveplan than generated by your computer) does not fit in: Do you believe that the style of diving you mentioned has been used as a database on which the deco algorithms were based upon? If yes: Poseidon is on your side anyway, you may even dump the computer. If no: Why don't you dump the computer anyway? ;-) My point of view here is, that a certain amount of variation in a dive is irrelevant, as long as you keep a sane ascent profile. A computer may help here to create, from the numbers, an idea of the geometric porperties of a good ascent curve. This is based on the notion that _all_ sane and safe ascent profiles look similar, from affine to congruent. If decompression is a substantial part of the dive, the curves still look the same. You just have to decide how much you really have to forgo, if you keep to a standard ascent profile from the beginning. Matthias > Of the dives you mention, which ones would have not fitted > in here: [quoted text clipped - 4 lines] > I bet this would leave you with a) sufficient bottom time > b)sufficient gas Not likely. I don't disagree with your strategy of "one size fits all" ascent schedule, but its air consumption will be roughly SAC * 30 minutes @ 1.5 ATM. Simplistically, if we double the ATM, we cut the time in half, which means that this schedule consumes the equivalent of 15 minutes @ 3 ATM, or 60fsw. YMMV, but I hardly think that a 15 minute reduction in bottom time is small enough to be disregarded for this application. Or even my own, where I'm hunting for photo subjects. > My point of view here is, that a certain amount of variation > in a dive is irrelevant, as long as you keep a sane ascent > profile. Sure. Nevertheless, one of my concerns with this conservative approach to all dives in a ~4 dives/day schedule is that the avoidance of the above schedule means 2 extra hours in the water each day, and thus, a highe exposure to warm water hypothemia, which may lead to other issues and/or trades. > If decompression is a substantial part of the dive, the > curves still look the same. True for a given consistent input. Problem here is that the long/ short compartments all have different half-times that, while it may not really change the "shape", it does affect the scales. -hh > > Of the dives you mention, which ones would have not fitted > > in here: [quoted text clipped - 37 lines] > short compartments all have different half-times that, while it may > not really change the "shape", it does affect the scales. I challenge anyone reading to get bent on an AL80. Soon as they do, we'll put them in the books as the first. "Scott" <pugetsounddiver@gmail.com> pounded away at his keyboard resulting in: :I challenge anyone reading to get bent on an AL80. Is it ok to read about it in Alert Diver? Seems to be a monthly event. Actually doing it on purpose seems a bit drastic. Dan Bracuk Never use a big word when a diminutive one will do. > "Scott" <pugetsounddiver@gmail.com> pounded away at his keyboard > resulting in: [quoted text clipped - 5 lines] > > Actually doing it on purpose seems a bit drastic. Again you make my point. > I challenge anyone reading to get bent on an AL80. > > Soon as they do, we'll put them in the books as the first. I'll bet I could. But it would have to be a very high six figure bet for me to do it. But this whole thread is beginning to sound like an angels on the head of a pin argument. Like Lee, I like the convenience of a computer when I'm diving close to the edge. Like Magilla, I can do most of it in my head. Like you, I've done that dive so many times I could do it in my sleep. You guys are getting awful bitchy over nothing at all. esg > > I challenge anyone reading to get bent on an AL80. > [quoted text clipped - 9 lines] > > You guys are getting awful bitchy over nothing at all. It's rec.scuba. We do good bitchy. JF > > I challenge anyone reading to get bent on an AL80. > > [quoted text clipped - 11 lines] > > esg Maybe we should turn it into a gun thread.... > Maybe we should turn it into a gun thread.... I have a gun table....... > > Maybe we should turn it into a gun thread.... > > I have a gun table....... ***** >> Maybe we should turn it into a gun thread.... > > I have a gun table....... I'm waiting on the installation of a couple thousand dollars worth of cabinets for my reloading supplies. Lee > I'm waiting on the installation of a couple thousand dollars worth of > cabinets for my reloading supplies. You're not going to be drilling holes through walls again, are you? <evil-grin> >> I'm waiting on the installation of a couple thousand dollars worth of >> cabinets for my reloading supplies. > > You're not going to be drilling holes through walls again, are you? > <evil-grin> Not anywhere near a drain pipe, no. Lee > Not anywhere near a drain pipe, no. So, you're going to try for the water supply lines this time? <evil-grin> > I challenge anyone reading to get bent on an AL80. > > Soon as they do, we'll put them in the books as the first. You probably should qualify that as being a single dive on a day with an AL80... On Jul 12, 9:56 pm, Grumman-581 <grumman...@DIE-SPAMMER-SCUM- gmail.com> wrote: > On Thu, 12 Jul 2007 16:16:19 -0700, "Scott" > [quoted text clipped - 5 lines] > You probably should qualify that as being a single dive on a day with > an AL80... You probably need a lot more qualifiers. Otherwise, it's easy. Dive to 200' on air. Stay 15 minutes. Make a rapid ascent (200 fpm). What's the likelihood of getting bent? >> I challenge anyone reading to get bent on an AL80. >> >> Soon as they do, we'll put them in the books as the first. > > You probably should qualify that as being a single dive on a day with > an AL80... I tried to do it once with a 72. I didn't succeed. > I challenge anyone reading to get bent on an AL80. > > Soon as they do, we'll put them in the books as the first. Been there, done that, twice, but it took more than one dive both times. >I challenge anyone reading to get bent on an AL80. > >Soon as they do, we'll put them in the books as the first. Hmmm. I know a guy who got bent last October on an AL80 in Australia. It was multiple dives over multiple days on air but he was using an AL80 for all of his dives. > >I challenge anyone reading to get bent on an AL80. > > [quoted text clipped - 3 lines] > It was multiple dives over multiple days on air but he was using an > AL80 for all of his dives. Don't make me do it. >> >I challenge anyone reading to get bent on an AL80. >> > [quoted text clipped - 5 lines] > >Don't make me do it. Do what? > Of the dives you mention, which ones would have not fitted > in here: [quoted text clipped - 4 lines] > I bet this would leave you with a) sufficient bottom time > b)sufficient gas Not likely. I don't disagree with your strategy of "one size fits all" ascent schedule, but its air consumption will be roughly SAC * 30 minutes @ 1.5 ATM. Simplistically, if we double the ATM, we cut the time in half, which means that this schedule consumes the equivalent of 15 minutes @ 3 ATM, or 60fsw. YMMV, but I hardly think that a 15 minute reduction in bottom time is small enough to be disregarded for this application. Or even my own, where I'm hunting for photo subjects. > My point of view here is, that a certain amount of variation > in a dive is irrelevant, as long as you keep a sane ascent > profile. Sure. Nevertheless, one of my concerns with this conservative approach to all dives in a ~4 dives/day schedule is that the avoidance of the above schedule means 2 extra hours in the water each day, and thus, a highe exposure to warm water hypothemia, which may lead to other issues and/or trades. > If decompression is a substantial part of the dive, the > curves still look the same. True for a given consistent input. Problem here is that the long/ short compartments all have different half-times that, while it may not really change the "shape", it does affect the scales. -hh >>Of the dives you mention, which ones would have not fitted >>in here: [quoted text clipped - 6 lines] > > Not likely. Well, I don't do the kind of dives Lee referred to, in that I agree to call my numbers a bit on the conservative, if not prohibitive side. Still I think that it is possible to come to a more adequte setting, which would fit in. It affords some practice, and until that, using the computer is helpful not only to monitor, but more so to reassure of what one is doing, because strict use of the tables would worry most people. Seeing the computer clear earlier helps in deciding wether the itching comes from sea lice, or bends (eg) > I don't disagree with your strategy of "one size fits all" ascent > schedule, but its air consumption will be roughly SAC * 30 minutes @ [quoted text clipped - 7 lines] > small enough to be disregarded for this application. Or even my own, > where I'm hunting for photo subjects. Agreed. My numbers fit better for mediterrnean dives, with a mean depth of 33 or so meters. >>My point of view here is, that a certain amount of variation >>in a dive is irrelevant, as long as you keep a sane ascent [quoted text clipped - 7 lines] > highe exposure to warm water hypothemia, which may lead to other > issues and/or trades. This is far out of the reach of any computer model reality as well, RBGM fudge factors or not. >>If decompression is a substantial part of the dive, the >>curves still look the same. > > True for a given consistent input. Problem here is that the long/ > short compartments all have different half-times that, while it may > not really change the "shape", it does affect the scales. Thanks for adding the part that I omitted ;-). That is quite right. In fact, it may lead sooner or later to the creation of a table were the decompression curve is one ( plus more or less conservative parallels solid SS316 wire in a rectangular mesh, the edges being sqare or hex fixed/rotational rods which different scales for depth and time. To ascend, just slide along the wire. Matthias > Well, I don't do the kind of dives Lee referred to, in that I agree to > call my numbers a bit on the conservative, if not prohibitive side. Not many people do the kind of dives I referred to except during lobster season. Even in lobster season, I would be unlikely to dive that way if it weren't on a rather expensive two and a half day spearfishing and lobstering trip. Literally, we're in and out of the water about as fast as possible all day long with breaks only for breakfast and lunch. As for being conservative, I dispute any claim that I'm not. Your inability to safely match my style on these dives is not because I'm less conservative, it's because I have better, more up to date information. Your last input is just before you step off the boat. Mine is updated continuously during the dive. That's the whole point. > Still I think that it is possible to come to a more adequte setting, which > would fit in. It affords some practice, and until that, using the computer > is helpful not only to monitor, but more so to reassure of what one is > doing, because strict use of the tables would worry most people. > Seeing the computer clear earlier helps in deciding wether the itching > comes from sea lice, or bends (eg) There's that too. >>Well, I don't do the kind of dives Lee referred to, in that I agree to >>call my numbers a bit on the conservative, if not prohibitive side. [quoted text clipped - 8 lines] > to safely match my style on these dives is not because I'm less > conservative, it's because I have better, more up to date information. ;-). You seem anxious not to tell which computer you use. Please do, and will probably name you one which would give you some penalty stops. >Your > last input is just before you step off the boat. Mine is updated > continuously during the dive. That's the whole point. You mean I am not using my brain when diving? On some dives, I'd rather think I'd lose input when I am using a computer ( and believe it's numbers). The most similar to the dives you describe is hwen we train students to do rescue ascents. They have to recover an "unconscious" diver from depth (depends, mostly between 18 and 12m) and bring him up, while maintaining airway control and proper ascent speed. I have limited my number of trials to max 4, formerly done 5 as well, but it really gets you tired. Deco obligation? None. Bends? None. Best way to dive? Absolutely not. Remember we have to differentiate between what you and I, Curtis, Cliff, Scott, Al, Doug, etc. do, and those who get to the surface by an uncontrolled ascent from 10 m, screaming, "I don't wanna die", while being in perfect health. Sometimes "cooperative" divemaster even help them get a chamber ride. Matthias > ;-). You seem anxious not to tell which computer you use. > Please do, and will probably name you one which would give you some > penalty stops. Not at all. I've said it more than once in this thread. I use an Oceanic Nitrox hocky puck, sometimes a Genesis made by the same manufacturer. It's fine for single gas dives. While it has some built in conservatism, it's not as conservative as many newer models. I also have a NiTek Duo and a NiTek He. Both are more conservative than the Oceanic and Genesis, but make up for it by being able to deal with a second gas or, in the case of the He, 7 gases total. I bought the He because it displays information I want which the Duo does not. > You mean I am not using my brain when diving? Earth to Matthias, your brain is the processor, it's not input. > On some dives, I'd rather think I'd lose input when I am using a computer > ( and believe it's numbers). You'll have to explain why more timely information equates, in your mind, to less input. > The most similar to the dives you describe is hwen we train students to do > rescue ascents. They have to recover an "unconscious" diver from depth [quoted text clipped - 3 lines] > it really gets you tired. Deco obligation? None. Bends? None. Best way to > dive? Absolutely not. How many per day take 40 to 60 minutes? > Remember we have to differentiate between what you and I, Curtis, Cliff, > Scott, Al, Doug, etc. do, and those who get to the surface by an > uncontrolled ascent from 10 m, screaming, "I don't wanna die", while being > in perfect health. Sometimes "cooperative" divemaster even help them get a > chamber ride. We don't have to differentiate in this case. I've not once denied that most dives can be done without a computer or that, for most diving, they're anything more than a convenience, something that does part of the job for the diver, freeing him or her to think of other things. My point, my only point, is that there are things you can do with a computer than you can't do without one. Unplanned profiles, when the water is deep enough, you stay down long enough, and do enough of them, is one of those things. Id only takes one example to prove my point. You'd think it would be conceded by now. Lee >>;-). You seem anxious not to tell which computer you use. >>Please do, and will probably name you one which would give you some [quoted text clipped - 4 lines] > fine for single gas dives. While it has some built in conservatism, it's not > as conservative as many newer models. Well you can do dives with the puck where a Suunto would just quit service, or begin to scream becuse of the Fuss Factors. Input in, garbage out. So IMHO it is not the computer alone which allows you to do the things you do, but the the fact, that you and any divewise healthy one can do the same. An otherwise omnisavant alien (not necessarily an illegal one) would not know wether you used a computer or nor. Your use of a computer as an indispensable tool would seem a more applicable statement, when you actually have to follow obligatory advice from your computer. I see no reference to this in your descriptions. Btw, does your computer give the information "mean depth" during the dive, or does it generate a in time profile graph? This would seem to me the most relevant information a computer could give, in these multilevel dives. > I also have a NiTek Duo and a NiTek He. Both are more conservative than the > Oceanic and Genesis, but make up for it by being able to deal with a second [quoted text clipped - 10 lines] > You'll have to explain why more timely information equates, in your mind, to > less input. Well, not less input, to be exact, but sometimes the same input is processed differently in a computer than in my brain. Or in another computer. We had a case my my Aladin showed onl 17m, while our buddies Suunto summed up 45 very quickly. Kind of worried the guy. My option is always brain override computer. >>The most similar to the dives you describe is hwen we train students to do >>rescue ascents. They have to recover an "unconscious" diver from depth [quoted text clipped - 5 lines] > > How many per day take 40 to 60 minutes? That is normally cold water rec dives, with 12l-14l(2x7) bottles. These training dives serie up to normally three in a row, each of them lasting about 30 minutes. Go down, swim about, have someone "have" an accident, get up, to the beach, hand student over to instructor who does the resuscitation skill evaluation etc., get down with the next group. In warmer water my rec dives are mostly 70 minutes, and two to three of them per day. In the Red Sea, I can sometimes extend to 90 min, longest there was two hours on a 15l bottle. My favorite dive spots are just a bit deeper, by habitude, location, and to avoid the shallow water slime in the mediterranean. Matthias >>Remember we have to differentiate between what you and I, Curtis, Cliff, >>Scott, Al, Doug, etc. do, and those who get to the surface by an [quoted text clipped - 13 lines] > > Lee Matthias Voss <spammat.voss@gmx.de> pounded away at his keyboard resulting in: :Btw, does your computer give the information "mean depth" :during the dive, or does it generate a in time profile :graph? This would seem to me the most relevant information a :computer could give, in these multilevel dives. That's nice but unnecessary information. All you need to know during a dive is how deep you are and how much longer you can stay at that depth. Dan Bracuk Never use a big word when a diminutive one will do. > Matthias Voss <spammat.voss@gmx.de> pounded away at his keyboard > resulting in: [quoted text clipped - 6 lines] > a dive is how deep you are and how much longer you can stay at that > depth. I beg to differ. Mean depth is valuable for overall tissue load, and the graph for shaping the ascent curve. Matthias Matthias Voss <spammat.voss@gmx.de> pounded away at his keyboard resulting in: :I beg to differ. :Mean depth is valuable for overall tissue load, and the :graph for shaping the ascent curve. Ascent curve? You must be talking tech diving. I'm talking rec diving. Dan Bracuk Never use a big word when a diminutive one will do. > Matthias Voss <spammat.voss@gmx.de> pounded away at his keyboard > resulting in: [quoted text clipped - 5 lines] > Ascent curve? You must be talking tech diving. I'm talking rec > diving. A familiar misconception ;-) you're welcome. Matthias Matthias Voss pounded > :I beg to differ. > :Mean depth is valuable for overall tissue load, and the > :graph for shaping the ascent curve. Overall tissue load is valuable why? > Matthias Voss pounded > [quoted text clipped - 3 lines] > > Overall tissue load is valuable why? Because you'd might want to offload some. More takes longer to. Matthias >>>:I beg to differ. >>>:Mean depth is valuable for overall tissue load, and the [quoted text clipped - 4 lines] > Because you'd might want to offload some. > More takes longer to. You're going to have to be clearer than that in order to communicate the issue. As far as I know, nitrogen issues are tissue specific. The gas goes into and comes out of different tissues at different rates. Note that I'm not talking about tissue compartments, an artificial construct to model, but not necessarily match, the performance of real tissues. I'm talking about actual body tissues. DCS shows up first in only one place. While you can certainly come up with a profile that will bend you in more than one place, I would assume that someone planning on not being bent, who does not violate all the rules he's using for that plan, whether based on tables or a computer, is unlikely to make a mistake drastic enough to bend all tissues. I use average depth, which my Citizen HA tells me, for SAC calculations and to get a general impression of the dive, but not for decompression planning purposes. Am I missing something or are we reading the same words without interpreting them the same way? Oceanic provides a free simulator that I've found to be quite interesting. One of the things it does, which the actual computer does not do, is show each of the compartments it's working with. You can tell, as you take the simulator through the dive, how much the calculated loading is for each compartment. It's a nice learning tool as well as a pretty good planning tool. I assume it's still available on the Oceanic website. If not, those that would like a copy need only send me a request from a real e-mail address. Please use "Simulator" in the subject line so I don't accidentally trash your message thinking it's spam. Lee >>>>:I beg to differ. >>>>:Mean depth is valuable for overall tissue load, and the [quoted text clipped - 15 lines] > all the rules he's using for that plan, whether based on tables or a > computer, is unlikely to make a mistake drastic enough to bend all tissues. I used "overall" in the meaning that I want to be aware of the status the relevant tissues are in. An overall term, as one generated to mirror in a single number a representative tissue state, might be regarded as not precise enough to predict possible problem areas. > I use average depth, which my Citizen HA tells me, for SAC calculations and > to get a general impression of the dive, but not for decompression planning > purposes. Am I missing something or are we reading the same words without > interpreting them the same way? I would avoid the word planning here. When I plan a dive, wit |
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