fishmonkey1
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Probably a very noob question, but why do you need to do it with pure oxygen? Why not just do it with air?
anyone want the truth and science on inwater recompression? It's incredibly effective
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You can recompress on air. Not very efficient but has been done. Better to use something with less N2 to accelerate the process relative to the heat units lost per minute.
halocline
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Kevrumbo
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Only IWR case I know of (ironically, the liveaboard had a Recompression Chamber that was not usable in this instance):
Oh Dear.. You're "bent" and a long way from home.. IWR anyone?
Decision Flow-Chart for IWR:
http://rubicon-foundation.org/graphi...IWR_Tx_Alg.jpg
Copy of the Pyle IWR Method/Table I always carry on my overseas Tech Wreck Trips:
File
yle IWR.jpg - Wikipedia, the free encyclopedia
Oh Dear.. You're "bent" and a long way from home.. IWR anyone?
Decision Flow-Chart for IWR:
http://rubicon-foundation.org/graphi...IWR_Tx_Alg.jpg
Copy of the Pyle IWR Method/Table I always carry on my overseas Tech Wreck Trips:
File
yle IWR.jpg - Wikipedia, the free encyclopediaDevon Diver, please read the actual article. The whole thing. Don't just skim it and pull quotes you like. The data sets clearly indicate that the subjects were "winging it", and it was statistically INCREDIBLY effective - even when they winged it. And if you want to extrapolate the information about the single diver who did multiple attempts of IWR, after LOOOOONNNNG delays, then you may. But I said very clearly in my very first post that IWR is something you don't leave port for -- you are in the water, or on a boat, and you go back down. Simple as that. I also was clear to add in my first post that once there is a delay or someone is onshore, it makes much more sense to just go to a chamber.
Culturally, we are so afraid of things for which we don't have a metric, even though they may be of great benefit. And just so you can all internalize this, ************AAAAAAAAAAALLLLLLLLLLLLLLLLLLLLLL********** theory regarding decompression is complete voodoo as it is. Science only has the most superficial understanding of how it actually works. We are still in the dark ages. This is not to put down scientists, it's to say that we know so little. Even the DSAT table that padi uses, only has something like 1200 data sets (or simulated dives in a chamber with a doppler radar checking for bubble counts).... for a couple hundred squares on the table corresponding to a pressuregroup/depth/time. If you think a dozen simulated dives in a chamber to create a "limit" or a "pressure group" on the table is "definitive science"...... well, it isn't. Diving is voodoo. Decompression theory is voodoo. And IWR is also voodoo. But it happens to be that even when people "wing it", they still get great results. We shouldn't shun IWR because one dummy decided, over a period of multiple days, to attempt multiple sessions of IWR that were not effective - and were only exacerbating symptoms.
Furthermore, all the existing table data we *do* have, that is "more precise" in a manner of speaking, is derived from taking bubbles counts in the bloodstream during and after ascent of a simluated dive in a chamber. You do not need to be a biologist to understand that by the time there is a nucleated bubble in your bloodstream it is possible smaller bubbles may have come from a tissue, and nucleated into larger bubbles. So what in the heck happened to the tissue that it came out of? what happens to my nerve cells on ascent? what happens to my liver? or heart? or muscles? what happens to my mitochondria? can anyone answer this with conviction? no? why not?
BECAUSE IT IS VOODOO.
We know next to nothing. Honestly. Anyone who thinks we actually have a grasp on any of this is nuts. This is why I personally choose not to do decompression diving. Because I don't have a whole lot of reservations asserting that even dives well with table limits can be harmful to our health. I dive anyway because I love diving. But I know that more than one dive per day is absolutely perjudicial to my health. No qualms asserting that *whatsoever*. It is not clear if one dive per day is good or bad for you, but a repetitive dive, is absolutely going to have a negative impact on your health. We make a tradeoff, and because we love diving, the norm is to dive more than once a day. Bubble formation, even "silent" bubbles, will have an impact at the very least, on capillary circulation. This is not good. But still, I dive. I am no longer working as a full time DM, grinding out four dives a day, everyday, because it destroys your health.
Here is what I am comfortable asserting, understanding that all of diving and decompression theory is in fact voodoo:
the 500+ data sets from the original article is every bit as scientifically important as the original DSAT tables. One is not more important than the other, but they are both incredibly valuable sets of data. The IWR data is slightly less precise, but the information gleaned from the data sets is profoundly important and indicates a new way of communicating to the dive community about IWR is absolutely critical. When we step outside a legal framework based in fear and liability, the net utility of the world, and of diving, would be improved. Obviously, DAN can't just start recommending IWR because even if hundreds of people might be able to completely prevent a case of DCS, if one person gets out of the water with a problem, they get sued, because "but DAN said it's ok..............". But from a rational individual perspective, why should we talk about these things?
I want to communicate very clearly to every single reader in this forumn, I will be doing IWR if it ever comes to it. Simple as that. I will endorse it with my actions, should I *knock wood* ever need to do so. I have worked alongside hundreds of dive professionals, in five countries, and three continents. I think, live, eat, sleep, breath - diving. And this is my choice. I have had mild decompression symptoms from working as a DM and doing 4 dives a day, everyday, to the tune of numb hands and feet when first awakening in the morning. I also had my own dive school and compressor. I have done things wrong. I have done things right. I am fallible. I am human. But I am a very experienced diver and instructor, and this is what I choose. What anyone chooses to do is up to them, and frankly I don't know what I would do if I were in fact faced with a bent customer displaying acute symptoms onboard a boat, but this is what I am doing for me. If I ever randomly meet any of you, or dive with you, you will know what to expect from me, in an emergency.
I hope that my assertion peels back some of the taboo associated with concepts in IWR amongst recreational divers.
You all need to be fully cognisant of two things in your own general decisions about diving - 1. legal liablity frameworks destroy concepts of net utility, or net benefit, because of fear from an individual lawsuit - this marginalizes IWR. 2. You think it's impossible that individuals constructing a dive table might have either a philosophical or financial reason for pushing trends of the dive community in a particular direction? Maybe people want to prove diving is safe, so they find data to prove this. Maybe people want to make money off diving, so subconsciously they approve of practices that make more money, without internalizing risk to the individual. Because these factors exist, "science" is not sitting back and observing, but rather, science is searching for an answer, and perhaps biasing the end conclusion based on that focused search. I am not throwing stones at anyone in particular - I am saying that factors like these absolutely exist. You don't need to trust dive table "safety", or "science" any more than you trust a posted speed limit sign around a curved road in the woods. It could be an easy, on-camber turn with an overly cautious speed limit, or it could be the last hairpin you ever drive. you feel me?
IT IS ALL "VOODOO". Ask hard questions. Keep and open mind.
Culturally, we are so afraid of things for which we don't have a metric, even though they may be of great benefit. And just so you can all internalize this, ************AAAAAAAAAAALLLLLLLLLLLLLLLLLLLLLL********** theory regarding decompression is complete voodoo as it is. Science only has the most superficial understanding of how it actually works. We are still in the dark ages. This is not to put down scientists, it's to say that we know so little. Even the DSAT table that padi uses, only has something like 1200 data sets (or simulated dives in a chamber with a doppler radar checking for bubble counts).... for a couple hundred squares on the table corresponding to a pressuregroup/depth/time. If you think a dozen simulated dives in a chamber to create a "limit" or a "pressure group" on the table is "definitive science"...... well, it isn't. Diving is voodoo. Decompression theory is voodoo. And IWR is also voodoo. But it happens to be that even when people "wing it", they still get great results. We shouldn't shun IWR because one dummy decided, over a period of multiple days, to attempt multiple sessions of IWR that were not effective - and were only exacerbating symptoms.
Furthermore, all the existing table data we *do* have, that is "more precise" in a manner of speaking, is derived from taking bubbles counts in the bloodstream during and after ascent of a simluated dive in a chamber. You do not need to be a biologist to understand that by the time there is a nucleated bubble in your bloodstream it is possible smaller bubbles may have come from a tissue, and nucleated into larger bubbles. So what in the heck happened to the tissue that it came out of? what happens to my nerve cells on ascent? what happens to my liver? or heart? or muscles? what happens to my mitochondria? can anyone answer this with conviction? no? why not?
BECAUSE IT IS VOODOO.
We know next to nothing. Honestly. Anyone who thinks we actually have a grasp on any of this is nuts. This is why I personally choose not to do decompression diving. Because I don't have a whole lot of reservations asserting that even dives well with table limits can be harmful to our health. I dive anyway because I love diving. But I know that more than one dive per day is absolutely perjudicial to my health. No qualms asserting that *whatsoever*. It is not clear if one dive per day is good or bad for you, but a repetitive dive, is absolutely going to have a negative impact on your health. We make a tradeoff, and because we love diving, the norm is to dive more than once a day. Bubble formation, even "silent" bubbles, will have an impact at the very least, on capillary circulation. This is not good. But still, I dive. I am no longer working as a full time DM, grinding out four dives a day, everyday, because it destroys your health.
Here is what I am comfortable asserting, understanding that all of diving and decompression theory is in fact voodoo:
the 500+ data sets from the original article is every bit as scientifically important as the original DSAT tables. One is not more important than the other, but they are both incredibly valuable sets of data. The IWR data is slightly less precise, but the information gleaned from the data sets is profoundly important and indicates a new way of communicating to the dive community about IWR is absolutely critical. When we step outside a legal framework based in fear and liability, the net utility of the world, and of diving, would be improved. Obviously, DAN can't just start recommending IWR because even if hundreds of people might be able to completely prevent a case of DCS, if one person gets out of the water with a problem, they get sued, because "but DAN said it's ok..............". But from a rational individual perspective, why should we talk about these things?
I want to communicate very clearly to every single reader in this forumn, I will be doing IWR if it ever comes to it. Simple as that. I will endorse it with my actions, should I *knock wood* ever need to do so. I have worked alongside hundreds of dive professionals, in five countries, and three continents. I think, live, eat, sleep, breath - diving. And this is my choice. I have had mild decompression symptoms from working as a DM and doing 4 dives a day, everyday, to the tune of numb hands and feet when first awakening in the morning. I also had my own dive school and compressor. I have done things wrong. I have done things right. I am fallible. I am human. But I am a very experienced diver and instructor, and this is what I choose. What anyone chooses to do is up to them, and frankly I don't know what I would do if I were in fact faced with a bent customer displaying acute symptoms onboard a boat, but this is what I am doing for me. If I ever randomly meet any of you, or dive with you, you will know what to expect from me, in an emergency.
I hope that my assertion peels back some of the taboo associated with concepts in IWR amongst recreational divers.
You all need to be fully cognisant of two things in your own general decisions about diving - 1. legal liablity frameworks destroy concepts of net utility, or net benefit, because of fear from an individual lawsuit - this marginalizes IWR. 2. You think it's impossible that individuals constructing a dive table might have either a philosophical or financial reason for pushing trends of the dive community in a particular direction? Maybe people want to prove diving is safe, so they find data to prove this. Maybe people want to make money off diving, so subconsciously they approve of practices that make more money, without internalizing risk to the individual. Because these factors exist, "science" is not sitting back and observing, but rather, science is searching for an answer, and perhaps biasing the end conclusion based on that focused search. I am not throwing stones at anyone in particular - I am saying that factors like these absolutely exist. You don't need to trust dive table "safety", or "science" any more than you trust a posted speed limit sign around a curved road in the woods. It could be an easy, on-camber turn with an overly cautious speed limit, or it could be the last hairpin you ever drive. you feel me?
IT IS ALL "VOODOO". Ask hard questions. Keep and open mind.
John from the burg
Contributor
I'm not a full cave diver or trimix certed or even an instructor, but what i am, is someone who has spent their whole life around diving, pushing my own limits in search of huge fish.
I have many first hand experiences with iwr, omitted decos, forgot decos (not me lol), equipment malfunctions at depth and run ins with local wildlife leaving my or my buddies blood/air shooting into the gulf. One story is very relevant to this talk;
Lets say "my friend" and his dive buddy pull up to a submarine spring and drop the hook on the lip in 100 feet of water. We... ummmm... i mean they, are spearfishing over a hole that drops down to 200 feet at the very dark bottom. Diver one (1st mate) drops and diver two (capt) stays on the boat to prep for his dive, diver one flops over puts his head down and kicks for the bottom, pushing jacks out of the way he penetrates the hole (giggity) and keeps kicking. Last time he was here, the fish hit were at 165 so that was the target depth, however, part of the fun is that the fish don't stay there and when I... ****, when he hits 160 all thats around are a few jacks that followed down from 100 looking for a free meal. No worries, i have the 180&200 ft plans on my slate so down i go looking for some dinner and boy do i find it, at 180' a 40-50 lbs (biggest Ive ever seen) gag (odd) is so taken back by the light that he forgets to run and i stick him on the spine right behind the left eye. Instantly, a 400 lbs jew fish comes from ABOVE me and tail slaps my face so hard that my mask is knocked down and my reg/teeth are broken in the process (jew fish have broken more of my equipment than everything else combined), now our diver is 180 feet under water with a free flowing reg, bloody mouth and flooded mask, guess what his first thought was?
Damnit i lost that gag!!! We're a sick bunch i know lol.
Step one is find the 13 cube pony reg, then i sort out my mask add and start the kick up thinking, i should have brought the 19 cube. We are 4 minutes into the dive, i planned for 8 at 180 so we're ok right? Nope, I slow at the lip, dodge jacks, think about life and how stupid i am for not being prepared for this, mostly trying to keep myself calm and not suck all the air. Reach 40 feet and grab the line for my first stop, I know that theoretically, i can go straight up because i was only at depth for seconds, but good judgment got the better of me and i stay for my off gas at 40. Were now 9 minutes in and Ive been on the pony under stress for 5, feeling like hot **** for saving my own life i chill and slowly pull up to 15 feet, dive time 16 min and on the pony for 12, this in when i have to decide about iwr. I pull my slate off and wright "TANK NOW!!", then attach it to my gun and send it up the line with faith in my capt to help me out. Seconds later, my bud splashed w a 36% al40 in his hand, I have never been so happy to see a fresh tank in my life, we spend a few more minutes together on the line in the name of safety (lol) and climb on deck when the gshock clicked past 22.
Now, i know that a lot of things were wrong (including my fish getting away) on that dive but at the same time it worked out pretty well in the end. I put myself into a dangerous situation that may not have required the iwr but in the name of safety i did it and i would again. We don't plan for iwr but if it needs to happen I'm ready and able to make it happen, safety tank and reg at the ready, boat man paying attention and coming down to watch me during are things that are always there. Other things like ponys (cough cough) backup dive plans and heads up diving are just the way we operate, i know my plan and my buds plan down to the stops because i want him to do the same for me.
I realize most people will never do anything like this, and as spearfishers we break golden rules of diving all the time, but i look at it like this, everything in life is a compromise. What i feel is safe is absolutely not what others feel is safe, what i have a problem with, other people do all the time, life is dynamic and so is diving. You can sit here on the net and slam people for iwr but if i think its going to save my life then I'm doing it no matter what the internet says.
Btw no dcs symptoms at all and i can still see that fish in my... buds mind lol.
I have many first hand experiences with iwr, omitted decos, forgot decos (not me lol), equipment malfunctions at depth and run ins with local wildlife leaving my or my buddies blood/air shooting into the gulf. One story is very relevant to this talk;
Lets say "my friend" and his dive buddy pull up to a submarine spring and drop the hook on the lip in 100 feet of water. We... ummmm... i mean they, are spearfishing over a hole that drops down to 200 feet at the very dark bottom. Diver one (1st mate) drops and diver two (capt) stays on the boat to prep for his dive, diver one flops over puts his head down and kicks for the bottom, pushing jacks out of the way he penetrates the hole (giggity) and keeps kicking. Last time he was here, the fish hit were at 165 so that was the target depth, however, part of the fun is that the fish don't stay there and when I... ****, when he hits 160 all thats around are a few jacks that followed down from 100 looking for a free meal. No worries, i have the 180&200 ft plans on my slate so down i go looking for some dinner and boy do i find it, at 180' a 40-50 lbs (biggest Ive ever seen) gag (odd) is so taken back by the light that he forgets to run and i stick him on the spine right behind the left eye. Instantly, a 400 lbs jew fish comes from ABOVE me and tail slaps my face so hard that my mask is knocked down and my reg/teeth are broken in the process (jew fish have broken more of my equipment than everything else combined), now our diver is 180 feet under water with a free flowing reg, bloody mouth and flooded mask, guess what his first thought was?
Damnit i lost that gag!!! We're a sick bunch i know lol.
Step one is find the 13 cube pony reg, then i sort out my mask add and start the kick up thinking, i should have brought the 19 cube. We are 4 minutes into the dive, i planned for 8 at 180 so we're ok right? Nope, I slow at the lip, dodge jacks, think about life and how stupid i am for not being prepared for this, mostly trying to keep myself calm and not suck all the air. Reach 40 feet and grab the line for my first stop, I know that theoretically, i can go straight up because i was only at depth for seconds, but good judgment got the better of me and i stay for my off gas at 40. Were now 9 minutes in and Ive been on the pony under stress for 5, feeling like hot **** for saving my own life i chill and slowly pull up to 15 feet, dive time 16 min and on the pony for 12, this in when i have to decide about iwr. I pull my slate off and wright "TANK NOW!!", then attach it to my gun and send it up the line with faith in my capt to help me out. Seconds later, my bud splashed w a 36% al40 in his hand, I have never been so happy to see a fresh tank in my life, we spend a few more minutes together on the line in the name of safety (lol) and climb on deck when the gshock clicked past 22.
Now, i know that a lot of things were wrong (including my fish getting away) on that dive but at the same time it worked out pretty well in the end. I put myself into a dangerous situation that may not have required the iwr but in the name of safety i did it and i would again. We don't plan for iwr but if it needs to happen I'm ready and able to make it happen, safety tank and reg at the ready, boat man paying attention and coming down to watch me during are things that are always there. Other things like ponys (cough cough) backup dive plans and heads up diving are just the way we operate, i know my plan and my buds plan down to the stops because i want him to do the same for me.
I realize most people will never do anything like this, and as spearfishers we break golden rules of diving all the time, but i look at it like this, everything in life is a compromise. What i feel is safe is absolutely not what others feel is safe, what i have a problem with, other people do all the time, life is dynamic and so is diving. You can sit here on the net and slam people for iwr but if i think its going to save my life then I'm doing it no matter what the internet says.
Btw no dcs symptoms at all and i can still see that fish in my... buds mind lol.
John frmo the burg, that it an interesting story with good life lessons, but it is not an example of IWR. In IWR, you surface and have definite indications that you have DCS. Once you realize you have DCS, a decision is made to return to the water with the purpose of relieving the symptoms as you would have done had there been a chamber nearby.
John from the burg
Contributor
Wellll technically, I see you point, but its still the same basic thing, i just had the wits to stay under and not surface as oppose to climbing up then your elbow hurting then doing a recomp. I switched tanks and stayed under for longer to make sure i had no problems, if i had a ****ty bud or was alone then i would have had to jump up, switch, and re splash. I used my buddy and my best judgment to solve a perceived dcs problem 50 miles offshore by staying in the water longer than planned, what should we call that? Surprise deco? Improvised stage?
Lol.
Lol.
The reason IWR is controversial is that you go into the water knowing you have DCS. That is what makes it both dangerous and controversial. Staying at a stop depth for a longer period of time under such circumstances when you have no symptoms is a good idea and neither dangerous nor controversial.
But it was an interesting story.
John from the burg
Contributor
Ahhhh now i follow you, your saying because i didn't crack the surface, i was never in serious danger of a hit and i agree.
My thought process was that i ran short on air so had to come up from depth much faster than i would have without the ff, effectively putting me at risk and justifying the extra time in water.
My thought process was that i ran short on air so had to come up from depth much faster than i would have without the ff, effectively putting me at risk and justifying the extra time in water.
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