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Scuba Forum / General / January 2006Deco Calculations
OK, so the class won't be until August, but I got the book for Deco Procedures in advance. (And, no, I'm not planning any deco dives until the class.) What are people using for deco calculations? There seem to be several options, ranging from the USN tables to sundry computer programs. I'd appreciate any information about your experience with the alternatives and any pros and cons. John Eells > OK, so the class won't be until August, but I got the book for Deco > Procedures in advance. (And, no, I'm not planning any deco dives until > the class.) What are people using for deco calculations? There seem to > be several options, ranging from the USN tables to sundry computer > programs. I'd appreciate any information about your experience with the > alternatives and any pros and cons. I ride my computer like a dirtbike. I love that beeping noise it makes. Where ever it says I can go, I go, and then some. Tables are about as useful as carrying an abacus. It's a simple impossibility for a static, arbitrary equation to be more accurate than a mobile computer -continually- sampling a -variety- of different inputs to deliver a continually updating output. -Especially- on several consecutive dives. And the (archaic) tables are computer generated as well, just in a grossly more ignorant and non-updating fashion. > It's a simple impossibility for a static, arbitrary equation to be more > accurate than a mobile computer -continually- sampling a -variety- of > different inputs to deliver a continually updating output. Cite. >> It's a simple impossibility for a static, arbitrary equation to be more >> accurate than a mobile computer -continually- sampling a -variety- of >> different inputs to deliver a continually updating output. > > Cite. It's not a citable paradigm. Before you attack that, be prepared to counter-cite. But it's self evident to any rational level of thought. When you punch up numbers on your home computer, to print on a piece of paper, your desk top assumed your perfect square profile and your perfect descent and ascent rates (which it keeps to itself), and any variation from this perfect profile, how ever minor or major, and which is a matter of inevitability, detracts from the accuracy of calculations for any successive dive profiles. It's a blind guessing game. When I program my computer and take it on the dive with me, it tracks these descent and ascent rates (and water temp) -as they happen-, giving and taking credit for circumstances and parameters your tables are ABSOLUTELY blind to, making more accurate calculation not only on the current dive, but the next dives as well. There's no comparison. > When I program my computer and take it on the dive with me, it tracks > these descent and ascent rates (and water temp) -as they happen-, giving and > taking credit for circumstances and parameters your tables are ABSOLUTELY > blind to, making more accurate calculation not only on the current dive, but > the next dives as well. What computer are you using? > What computer are you using? Macintosh. >>What computer are you using? > > Macintosh. Isn't that kinda hard to strap on your wrist or attach to your regulator? >> When I program my computer and take it on the dive with me, it tracks >> these descent and ascent rates (and water temp) -as they happen-, giving [quoted text clipped - 5 lines] > > What computer are you using? I have Dive Rite, Dacor, Sunnto and an Oceanic on the way. <snip> > When I program my computer and take it on the dive with me, it tracks > these descent and ascent rates (and water temp) -as they happen-, giving and > taking credit for circumstances and parameters your tables are ABSOLUTELY > blind to, making more accurate calculation not only on the current dive, but > the next dives as well. This strikes me as very similar to football when the refs call for a measurement using the chains. The chain has a marker that they line up with one of the yard markers on the field. Then, the chain crew brings the chains out to where the ball is andthey line the marker up with that yardline again. Then, they "stretch" the chain to see if the ball was spotted short of the marker or not. It's all very accurate. At least, until you stop and remember that they just eyeballed the down markers to begin with. :-) > <snip> > [quoted text clipped - 16 lines] > all very accurate. At least, until you stop and remember that they just > eyeballed the down markers to begin with. :-) I wouldn't debate that at all. But -my- chain marker goes out on the field during play. Their chain marker stays in the gear locker. >> It's a simple impossibility for a static, arbitrary equation to be more >> accurate than a mobile computer -continually- sampling a -variety- of >> different inputs to deliver a continually updating output. > >Cite. Cite??? If you're asking for a "cite" on this then you simpley do not understand. Clearly, given that you're using the same (or equally good) decompression model, then you will get better results (closer to reality) from a real-time execution of that model, using actual conditions experienced, than you will from a pre-dive execution using necessarily less accurate estimates (guesses) of what you will experience. The "real-time execution" is what a dive computer does.  SignatureCharlie Hammond -- Hewlett-Packard Company -- Ft Lauderdale FL USA (hammond@not@peek.ssr.hp.com -- remove "@not" when replying) All opinions expressed are my own and not necessarily my employer's. >> It's a simple impossibility for a static, arbitrary equation to be >> more accurate than a mobile computer -continually- sampling a >> -variety- of different inputs to deliver a continually updating output. > > Cite. Basic math. Dive tables are generated using a large number of assumption about our dive profile - notably that we all dive a square profile - i.e. you descend to depth, don't vary from that depth, and then ascend from that depth straight to your deco stop. I've yet to meet a diver who dives like this; most of us hit our max depth, and then work our ways up from there (YMMV). Dive computers use the same mathematical models as the tables, but rather then assuming a square profile they continually monitor your depth (and hence gas absorption). Using that information the dive computer continually calculates your gas loading, remaining bottom time, deco stop depth/time, etc. As such it corrects for our less-then-square profiles (i.e. measures reality, rather then some engineers fantasy version of the real world). This has several advantages; firstly you get "credit" for the time you spend at less then your maximum depth. Secondly, you get credit for any offgassing which occurs while you ascend. Lastly, it gives you an added layer of safety, as it automatically accounts for any exceeding of your maximum planned depth. The net effect - more bottom time; and if doing deco - shorter deco stops. IMO tables still have a role - they can act as backup in case your computer bites the dust during a dive, and they are useful tools for planning (especially if you're planning on multiple dives). But during a dive, give me a computer. It keeps far better track of my dive profile then I can, and can better calculate my true gas loading then any table. Bryan > Basic math. Dive tables are generated using a large number of assumption > about our dive profile - notably that we all dive a square profile - i.e. > you descend to depth, don't vary from that depth, and then ascend from > that depth straight to your deco stop. I've yet to meet a diver who dives > like this; most of us hit our max depth, and then work our ways up from > there (YMMV). You guys really are missing the boat (pun intended). The assumption that all dive tables assume square profiles and that computers don't is simply untrue. OK, some dive tables do, but some don't. You can plan a multilevel dive using tables, particularly computerized tables. The only caviat being that, for them to be valid, you have to do what you planned. Dive computers do pretty much the same thing. Based on information they sample, they too calculate a series of square profiles. Their advantage is not their ability to manage multilevel dives. Their advantages is that they simplify the process and allow for changes in the plan during the dive. If you have not met any divers who plan their dives and stick closely to their plan, you have not met any technical divers. When multiple gases, significant depths and long decompression obligations are involved, tables are the norm. There really is no contest between computers and tables. For unplanned, or loosely planned recrational diving, tables simply can't compete with a good dive computer. For tighter controlled deep dives, multiple gases and accelerated decompression methods, there aren't any computers (that I know of) that can compete with tables cut specifically for that particular dive. Using the tool most appropriate for the job just makes good sense. For most of us, that's a computer. > Dive computers use the same mathematical models as the tables . . . Diver computers don't even use the same mathematical models as other dive computers. For that matter, neither do tables. Personally, I use Oceanic computers for my recreational diving. They provide me with consistent, basic, information with a minimum of paranoid conservatism. I pefer to start with the base line and add conservatism myself. I have, and occasionally use a DiveRite Nytec Duo for dives where I plan to use a higher PPO2 mix to accelerate modest decompression. It's more conservative than I would normally choose, but makes up for it by allowing me to change the gas, during the dive, that it uses for calculations. For any dive that involves what I consider significant decompression, I plan the dive with Deco Planner, stick pretty close to the plan, and manage the dive, according to the plan, with my Nytec Duo computer. YMMV. I could manage it as well, with a simple depth gauge and timer, but I like the additional information the computer provides. > It keeps far better track of my dive profile then I can, and can better > calculate my true gas loading then any table. Neither a computer, nor a set of tables, calculates your true gas loading. It's all theoretical, it's all an estimate, it's all done in hopes of being close enough to let you enjoy your dive without pain or death. Both work pretty well. Lee > "Bryan Heit" wrote > You guys really are missing the boat (pun intended). The assumption that > all dive tables assume square profiles and that computers don't is simply > untrue. OK, some dive tables do, but some don't. You can plan a multilevel > dive using tables, particularly computerized tables. True, but you still end up taking hits in terms of bottom & deco time due to the relatively small number of calculated steps. > Dive computers do pretty much the same thing. Based on information they > sample, they too calculate a series of square profiles. Their advantage is > not their ability to manage multilevel dives. Their advantages is that they > simplify the process and allow for changes in the plan during the dive. The profile generated by a dive computer is much more accurate then those done using tables. This is simply due to the sample rate - your computer basically strings a series of square profiles together, one square profile for each time point it measures. The sample rate between computers varies, but at the end of the day most computers will take hundreds, if not thousands of measures per dive. This is inherently more accurate then the 2-3 samples most multi-level dive planners allow for. In mathematical terms its an area under the curve type calculation. Rather then measuring the exact area (which would require an infinitely fast sample rate) you approximate by stringing together a series of averages taken from a finite number samples. Dive computers and tables both do the same type of calculation, but computers take more samples then either single, or multiple level dive tables, and therefore give a more accurate representation of what happened in the real world. > If you have not met any divers who plan their dives and stick closely to > their plan, you have not met any technical divers. When multiple gases, > significant depths and long decompression obligations are involved, tables > are the norm. I know many technical divers, and I'm well aware of the differences in diving. For that matter I plan my dives, and stick rather closely to my plan (albeit, more to optimize my multi-dive schedule, rather then for deco purposes). I am also well aware of the limitations of computers in technical diving. But I wasn't even trying to address the original question, but rather the Whistlers apparent confusion as to why a computer, taking a continued sample, is more accurate then a table based on a single, or at best four or five, samples. And even technical divers are loosing bottom time (or accumulating unneeded deco time) which could be avoided by a computer capable of taking on the kind of math needed for that type of diving. After all, they rarely spend 100% of their bottom time at the max depth they use for their calculations. After all, to stay at that floor would require that either the entire wreck/cave/dive site be perfectly flat, or that they limit themselves to the region of the site which is at the exact depth they planned for. In the real world that depth is the max depth they'll hit, and much of the bottom time is accumulated in areas above that depth. Just like in the good ol' days of rec diving, before we had computers or multi-level tables... > For tighter controlled deep dives, multiple gases and > accelerated decompression methods, there aren't any computers (that I know > of) that can compete with tables cut specifically for that particular dive. Yet. I'd be willing to bet that as technical diving becomes more popular that computers capable of taking into consideration the deeper depths, switching of gas mixtures, etc, will become available and accepted. I know rebreathers aren't that popular in many technical circles, but some of the newer rebreathers already are beginning to incorporate computers which are capable of taking into account different gas mixtures. Granted these computers usually only have to account for the O2/diluent ratio, but it is a step closer to being able to truly account for switching gases. >>Dive computers use the same mathematical models as the tables . . . > > Diver computers don't even use the same mathematical models as other dive > computers. For that matter, neither do tables. Notice I said "models", not "model". There most definitely is more then one way in which it is done. That said, most models are pretty much the same. It's only the method of approximation (i.e. tissue "compartments" vs. single compartment) and degree of conservatism that varies. Interestingly, the tissue compartment methods used in these types of models are nearly identical to the types of models I use to model drug absorption and breakdown at work. > Personally, I use Oceanic > computers for my recreational diving. They provide me with consistent, > basic, information with a minimum of paranoid conservatism. I've always wondered - is the excessive conservatism due to paranoia over DCS, or paranoia over libel... >>It keeps far better track of my dive profile then I can, and can better >>calculate my true gas loading then any table. > > Neither a computer, nor a set of tables, calculates your true gas loading. Bad wording on my part. Perhaps "closer approximation" would have been a better phrase. Bryan >> You guys really are missing the boat (pun intended). The assumption that >> all dive tables assume square profiles and that computers don't is simply >> untrue. OK, some dive tables do, but some don't. You can plan a >> multilevel dive using tables, particularly computerized tables. > True, but you still end up taking hits in terms of bottom & deco time due > to the relatively small number of calculated steps. The guys that are diving tables because of the diving they are doing, are staying down longer than anybody on a dive computer and, on the same dive, will consistently have shorter, at least equally safe decompression times on comparable dives. That's exactly why they use tables. >> Dive computers do pretty much the same thing. Based on information they >> sample, they too calculate a series of square profiles. Their advantage >> is not their ability to manage multilevel dives. Their advantages is >> that they simplify the process and allow for changes in the plan during >> the dive. > The profile generated by a dive computer is much more accurate then those > done using tables. Not at all. The difference is in planning and sticking to your plan only. > This is simply due to the sample rate - your computer basically strings a > series of square profiles together, one square profile for each time point > it measures. The sample rate between computers varies, but at the end of > the day >most computers will take hundreds, if not thousands of measures per dive. So do depth gauges. > This is inherently more accurate then the 2-3 samples most multi-level > dive planners allow for. Multilevel dive planners allow for as many depths as the user choses. In fact, computers are inhenently less accurate, deliberately so, when it comes to deco calculations. Every one of them adds some level of conservatism. That, however, isn't the point. The point is, a computer's biggest advantage is that it facilitates planning on the fly, something you can't do easily with tables. >> If you have not met any divers who plan their dives and stick closely to >> their plan, you have not met any technical divers. When multiple gases, >> significant depths and long decompression obligations are involved, >> tables are the norm. > I know many technical divers, and I'm well aware of the differences in > diving. For that matter I plan my dives, and stick rather closely to my [quoted text clipped - 4 lines] > computer, taking a continued sample, is more accurate then a table based > on a single, or at best four or five, samples. Whistler's not confused. >> For tighter controlled deep dives, multiple gases and accelerated >> decompression methods, there aren't any computers (that I know of) that >> can compete with tables cut specifically for that particular dive. > Yet. I'd be willing to bet that as technical diving becomes more popular > that computers capable of taking into consideration the deeper depths, > switching of gas mixtures, etc, will become available and accepted. There's one available right now. You might ask youself why the technical diving group has not embraced them. Whistler could tell you. > I know rebreathers aren't that popular in many technical circles, but some > of the newer rebreathers already are beginning to incorporate computers > which are capable of taking into account different gas mixtures. You clearly do not understand the technical community's opinion of rebreathers. They've been using them, when appropriate, for longer than most of the people here have been diving. > Granted these computers usually only have to account for the O2/diluent > ratio, but it is a step closer to being able to truly account for > switching gases. Their not exactly new. They've been around for a long time. >> Diver computers don't even use the same mathematical models as other dive >> computers. For that matter, neither do tables. > Notice I said "models", not "model". There most definitely is more then > one way in which it is done. That said, most models are pretty much the > same. It's only the method of approximation (i.e. tissue "compartments" > vs. single compartment) and degree of conservatism that varies. Nope. > Interestingly, the tissue compartment methods used in these types of > models are nearly identical to the types of models I use to model drug > absorption and breakdown at work. Because the mechanism is so similar. >> Personally, I use Oceanic computers for my recreational diving. They >> provide me with consistent, basic, information with a minimum of paranoid >> conservatism. > > I've always wondered - is the excessive conservatism due to paranoia > over DCS, or paranoia over libel... Yes. It's well known that you can't precisely predict nitrogen issues. There's just too many variables that affect the results. Any formula intended for use by everyone has to be based on the lowest common denominator. In some cases, there's added conservatism just in case. Suunto is well known for it. > Bad wording on my part. Perhaps "closer approximation" would have been a > better phrase. Much better. It's also another reason why tables work just as well as computers for those willing to plan their dives in detail and stick to the plan. Lee I think we're talking about different things here. I'm thinking more along the lines of approximation errors, whereas you seem to be thinking more along the lines of built-in conservatism. Oh well, I've never won any awards for clarity... >> Yet. I'd be willing to bet that as technical diving becomes more popular that computers capable of taking into consideration the deeper depths, switching of gas mixtures, etc, will become available and accepted. > There's one available right now. You might ask youself why the technical diving group has not embraced them. Whistler could tell you. You mean the VR2/VR3? >> Interestingly, the tissue compartment methods used in these types of models are nearly identical to the types of models I use to model drug absorption and breakdown at work. > Because the mechanism is so similar. Identical, actually. The only difference is that the metabolic rates we have to calculate for drugs get ignored in the SCUBA models, since none of the gases that we worry about are metabolized to any significant degree. This is why I said in my past post that there is very little in terms of the differences between the calculations used to derive the different SCUBA models. Although the methods used to estimate absorption, release and compartmentalization (if the model uses compartments) vary, as does the degree of conservatism, the underlying math remains the same. I've set to see a single SCUBA model that isn't based on LaPlace transforms. Methods to predict duration/depth of deco stops is another thing, but once again all of those models that I've looked at use LePlace transforms to predict the rate of degassing. The problem with the SCUBA models (and most of the drug models for that matter) is that much of the values we use for input are guesstimates - predictions often based on guess work and limited experimentation. Using Doppler to detect air bubbles in test subjects doesn't exactly give you the info you need for a SCUBA proper model - at best you get a rough idea of gas movement from tissue to blood. Implantable nitrogen monitors, and a couple dozen test divers (some of who would have to get DCS), would be the way to go. But the first item doesn't exist, and the second item would probably be very hard to find. >>> I've always wondered - is the excessive conservatism due to paranoia >>> over DCS, or paranoia over libel... > > Yes. That was supposed to be a joke. As I said, I'm rarely known for being clear. There is no question in my mind that the excessive conservatism of my computer is as much a product of liability as anything. Gotta make sure the 800lb heifers don't get DCS and sue. Downside is if you don't way 800lbs, and aren't litigious by nature, you get screwed ;-) Bryan > I think we're talking about different things here. I'm thinking more > along the lines of approximation errors, whereas you seem to be thinking > more along the lines of built-in conservatism. Oh well, I've never won > any awards for clarity... It's all a SWAG tempered by anyone with a reasonably functional homo sapiens Mk I. There are *mountains* of empirical evidence available to anyone who dares to look (tempered by anyone with a reasonably functional homo sapiens Mk I). There is a bigger mountain of bullshit that is used by salesmen to further paranoia and make money selling you sh.t you dont need, including a MAC or PC or Vyper or Aladin or other whiz-bang percundis WTF. >The only caviat being >that, for them to be valid, you have to do what you planned. There lies the rub. The fish usually plan my dives. <snip> Hey, first I've heard of you since Katrina... I tried sending email to your old cox.net email address, but no reply... How bad did your house get damaged? Still in the New Orleans area? ><snip> > >Hey, first I've heard of you since Katrina... I tried sending email to your >old cox.net email address, but no reply... How bad did your house get >damaged? Still in the New Orleans area? I bought a house in Gonzales. The house in Venetian Isles is toast. I guess I'm doin OK in the "new normal." <G> > I bought a house in Gonzales. The house in Venetian Isles is toast. > I guess I'm doin OK in the "new normal." <G> Glad to hear that ya'll at least survived... Did you evacuate and if so, where? That's a pretty good distance from Venetian Isles... Close enough to Baton Rouge that at least it should be above sea level (and perhaps more importantly, above storm surge level)... You going to rebuild in Venetian Isles? Oh, BTW, did Fort Pike survive? The house that I had in Slidell survived with just some limbs stripped from some of the trees from what I understand... It was north of I-12, so it was safe from the storm surge... We had sold it a few months before Katrina... We're back in the Houston area these days... >> I bought a house in Gonzales. The house in Venetian Isles is toast. >> I guess I'm doin OK in the "new normal." <G> > >Glad to hear that ya'll at least survived... Did you evacuate and if so, >where? Oh yeah, this one was "run for your life." We came up here to Gonzales. >That's a pretty good distance from Venetian Isles... Close enough to Baton >Rouge that at least it should be above sea level (and perhaps more >importantly, above storm surge level)... > >You going to rebuild in Venetian Isles? No. I loved it for 21 years, but no. >Oh, BTW, did Fort Pike survive? It's about the only thing on the island that did. It's either piles of debris or wiped clean; nothing left but pilings. >The house that I had in Slidell survived with just some limbs stripped from >some of the trees from what I understand... It was north of I-12, so it was >safe from the storm surge... We had sold it a few months before Katrina... >We're back in the Houston area these days... Kinda crowded, huh? <G> > Oh yeah, this one was "run for your life." Proof that regardless of what we saw on the news, not *everyone* in New Orleans was too stupid to realize what a forecasted Cat-5 storm meant... <grin> Of course, the latest reports say that it only struck New Orleans as a Cat-3... That says something about the design and construction of the levees, I guess... On the other hand, you were outside the levees so basically, you were seriously f.cked... How high was your house built above the water and how high did the water rise? > Kinda crowded, huh? <G> Well, Houston did get quite a few of the Katrina evacuees, but we didn't have anyone staying with us... We offered to a couple of our former co-workers on the Lockheed / Navy contract, but they were either already staying with family or their house had survived and they were living in it while waiting on the electricity to be restored... As for the new house in the Houston area, yeah, it's a bit more crowded than the previous one in Slidell... The one over there was a bit less than 4000 sq-ft (single story) plus a garage with room for 3 cars and a workshop... I'm down to a 2-car garage now, no workshop, and a HOA that is too fuckin stupid to approve my plans for expansion of my detached garage into an addition car area plus a workshop area without a full set of architectual drawings... Lot size is less than half of the 1+ acre lot we had over on Royal Golf Course in Slidell... Not as convenient to get to the airport either... Basically, I hate it, but *Grace* wanted the neighborhood for the schools... Oh well, another 8 years and Kaitlyn will be off to college and I can sell this one and build another one where I don't care about the fuckin' school district... >> Oh yeah, this one was "run for your life." > [quoted text clipped - 7 lines] >basically, you were seriously f.cked... How high was your house built above >the water and how high did the water rise? We were high enough. No water reached my main floor. Everything under the house was washed out. Most of the roof and half of the upper floor was blown out. I'll email you a couple of pictures. >> Kinda crowded, huh? <G> > [quoted text clipped - 15 lines] >and build another one where I don't care about the fuckin' school >district... > We were high enough. No water reached my main floor. Everything > under the house was washed out. That's kind of to be expected... One of the reasons that you build on pylons instead of just a large mound of dirt... > Most of the roof and half of the upper floor was blown out. I'll email you a > couple of pictures. I saw the photos... Quite a bit of damage... Pretty bad, but not as bad as I was originally thinking... I had expected to just see the pylons sticking up through the ground... Do you think that it is repairable or will it be a case of just tearing it down and starting over? Were there any houses that were built in Venetian Isles (or were just lucky enough) such that they had no damage after the storm? Considering the way that the water picked up the concrete sections of the I-10 "Twin Span" bridge and tossed them around, it would seem difficult to build a house that was completely hurricane and storm surge proof... >> We were high enough. No water reached my main floor. Everything >> under the house was washed out. [quoted text clipped - 10 lines] >through the ground... Do you think that it is repairable or will it be a >case of just tearing it down and starting over? I think it's totalled...my builder thinks it's totalled...the punk-a.s adjuster, working his first storm, taking his vast experience working construction in Missouri, thinks it can be fixed for 180k. I've requested a new adjuster and Farmer's told me they need contractors' estimates. I'm working on that. They think folks are desperate; I'm not. I will go all the way for policy limit. Do you think they want to face an Orleans Parish jury?? > Were there any houses that >were built in Venetian Isles (or were just lucky enough) such that they had >no damage after the storm? Considering the way that the water picked up the >concrete sections of the I-10 "Twin Span" bridge and tossed them around, it >would seem difficult to build a house that was completely hurricane and >storm surge proof... A few houses appear to have fared well, some are nothing but a clean slab and many in between. There were reports of a dozen tornadoes in the neighborhood. > I think it's totalled...my builder thinks it's totalled...the punk-a.s > adjuster, working his first storm, taking his vast experience working [quoted text clipped - 3 lines] > not. I will go all the way for policy limit. Do you think they want > to face an Orleans Parish jury?? When you first look at the photos, it looks like the building withstood the winds pretty good with not too much structural damage... The problem is that once the roof left, water came in and now you also probably have to rip out everything to ensure that you won't have a mold problem... I take it that you have what's left of the roof covered with a blue tarp right now to prevent further damage? The time it would take to 'repair' is probably longer than it would take to tear down and rebuild... Assuming that they do settle for the policy limit, are you going to rebuild or just sell the land and whatever rubble is sitting on there? How long did it take for all your utilities to be restored (electricity, gas, water, sewer, phone, etc)? > A few houses appear to have fared well, some are nothing but a clean > slab and many in between. There were reports of a dozen tornadoes in > the neighborhood. It take a lot of concrete to build a house above ground that can survive a tornado and storm surge... >> I think it's totalled...my builder thinks it's totalled...the punk-a.s >> adjuster, working his first storm, taking his vast experience working [quoted text clipped - 10 lines] >you have what's left of the roof covered with a blue tarp right now to >prevent further damage? There is only about 20% of the roof left. The punk-a.s adjuster told me it was my "responsibility to mitigate my damages." I told him that ship has sailed. If I got a giant crane and covered the house with a circus tent it would become a bag of water. It was several weeks before I could even visit the house. In that time, Rita dumped another ten inches of rain into the house. In my opinion, "further damage" is a joke. The builder said it would cost more to try to fix than to start over and that he wouldn't certify the result. It seems that the MO of the insurance companies is to offer a low ball settlement and hope desperate people take the money. I'm gonna fight! >The time it would take to 'repair' is probably >longer than it would take to tear down and rebuild... Assuming that they do [quoted text clipped - 8 lines] >It take a lot of concrete to build a house above ground that can survive a >tornado and storm surge... >>The only caviat being >>that, for them to be valid, you have to do what you planned. > There lies the rub. > The fish usually plan my dives. Exactly why I use a computer for most of my dives. Lee > If you have not met any divers who plan their dives and stick closely to > their plan, you have not met any technical divers. When multiple gases, > significant depths and long decompression obligations are involved, tables > are the norm. Some of us have learned to be quite flexible without a dive computer. > There really is no contest between computers and tables. For unplanned, > or loosely planned recrational diving, tables simply can't compete with a > good dive computer. Oh yeah, they can *compete*. Just because most prefer to take the "lazy way out". :-) > For tighter controlled deep dives, multiple gases and accelerated > decompression methods, there aren't any computers (that I know of) that > can compete with tables cut specifically for that particular dive. Yep. > Using the tool most appropriate for the job just makes good sense. For > most of us, that's a computer. For others, it is a bottom timer with standardized gasses & experience, works quite well. Curtis "\"Magilla\"" <cavey_curtis@$$ yahoo.com> pounded away at his keyboard resulting in: : Oh yeah, they can *compete*. Just because most prefer to take the "lazy :way out". :-) Yeah, like me. I dive for fun and looking at pretty fishies is much more fun than math. For me anyhow, everybody has their own likes and dislikes. Dan Bracuk If we don't succeed, we run the risk of failure. > Yeah, like me. I dive for fun and looking at pretty fishies is much > more fun than math. Yeah, but I dive for fun too. Sometimes for my own fun, sometimes to assist someone else's fun, sometimes merely to relax. Admit I'm easily entertained. I really don't find the math, or tracking my own dive, any more problematic than keeping trim, avoiding silt or controlling bouyancy. Just another skill a good diver should have. Figuring out what type of fish I see is more daunting than the math involved in a dive. > For me anyhow, everybody has their own likes and dislikes. Yep. Just figure that there is another side to the "need" for a dive computer to enjoy your diving, and limiting no dive computer usage to technical diving only is just that, limiting. Curtis "Magilla" wrote: >Admit I'm easily entertained. Nice to see that I'm not the only one. Life is so much more entertaining when you are easily entertained. >> There really is no contest between computers and tables. For unplanned, >> or loosely planned recrational diving, tables simply can't compete with a >> good dive computer. > > Oh yeah, they can *compete*. Just because most prefer to take the > "lazy way out". :-) I would think that committing your dive to pre-planned tables that restrict activities during the dive is the lazy way out. :-) >> Oh yeah, they can *compete*. Just because most prefer to take the >> "lazy way out". :-) > > I would think that committing your dive to pre-planned tables that > restrict activities during the dive is the lazy way out. :-) I guarantee I'm not near as "restricted" as you insinuate....... :-) Curtis >>> Oh yeah, they can *compete*. Just because most prefer to take the >>> "lazy way out". :-) [quoted text clipped - 3 lines] > > I guarantee I'm not near as "restricted" as you insinuate....... :-) You're still more restricted than I am. > Curtis >>> I would think that committing your dive to pre-planned tables that >>> restrict activities during the dive is the lazy way out. :-) >> >> I guarantee I'm not near as "restricted" as you insinuate....... :-) > > You're still more restricted than I am. I'll have to remember that. Curtis <-------grinning like the Cheshire Cat Y'all play nice, I'm heading to Nashville....... >>>> I would think that committing your dive to pre-planned tables that >>>> restrict activities during the dive is the lazy way out. :-) [quoted text clipped - 8 lines] > > Y'all play nice, I'm heading to Nashville....... Me, too. :-) ""Magilla"" wrote >> I would think that committing your dive to pre-planned tables that >> restrict activities during the dive is the lazy way out. :-) > > I guarantee I'm not near as "restricted" as you insinuate....... :-) Restricted is not the best word for diving your plan, but it's probably as good a word as we have to describe what we mean. Lee >>> There really is no contest between computers and tables. For unplanned, >>> or loosely planned recrational diving, tables simply can't compete with >>> a good dive computer. >> Oh yeah, they can *compete*. Just because most prefer to take the >> "lazy way out". :-) > I would think that committing your dive to pre-planned tables that > restrict activities during the dive is the lazy way out. :-) For me, it's more a matter of flexibility than laziness. I'll be the first to admit that I'm too lazy to plan most of my dives in detail, but that's OK since I enjoy unplanned diving more anyway. Who knows when, or for how long, during a dive, I'll want to be at my deepest point. For me, a big jewfish, shark, lobster opportunity, octopus, almost anything interesting, means the end of whatever I originally planned. Lee >> It's a simple impossibility for a static, arbitrary equation to be more >> accurate than a mobile computer -continually- sampling a -variety- of >> different inputs to deliver a continually updating output. > > Cite. No cite needed, "error" is concept, not statement. (note quotation marks surrounding word error) Why calculate to the ten-thousandth when rounding to the tenth will do? I suspect it's because some live by NDLs, some realize it's all deco and plan accordingly. Curtis ""Magilla"" wrote > Why calculate to the ten-thousandth when rounding to the tenth will do? Not only will do, but are more accurate than the theory on which all the calcualtions are based. > I suspect it's because some live by NDLs, some realize it's all deco and > plan accordingly. Well said. Lee > OK, so the class won't be until August, but I got the book for Deco > Procedures in advance. (And, no, I'm not planning any deco dives until > the class.) What are people using for deco calculations? There seem to > be several options, ranging from the USN tables to sundry computer > programs. I'd appreciate any information about your experience with the > alternatives and any pros and cons. I use a program on a PC or Palm Pilot. For Buhlmann with gradient factors, there's Decoweenie http://www.decoweenie.com/ and Dplan from GUE for the Palm and Decoplanner from GUE for the PC. For VPM, there is V Planner for PC or Palm http://www.hhssoftware.com/v-planner/ For RGBM, there is GAP http://www.gap-software.com/ If you look around, you will find others. If you can find ZPlan, it is a good Buhlman program and free. I use mostly DPlan and heavily modify the schedules it gives based on experience. I've been using the Buhlman schedules since before VPM became widely available, and it is what I know. For starting out, I would recommend V Planner, as it produces schedules that I think are the closest to correct. Most of the dive computers will have you run to the Buhlman ceiling, and that is definitely not the way I want to decompress. Even if you decide to use a dive computer, you should get one of the programs and play with it. |
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