changes a thing - nor does it present a "problem" - in terms of how I handle my vessel and the fact that the stores on it are free to be used by my friends who dive with me.
First, the law as I have been led to understand it (and IANAL, although I've paid for plenty of legal advice over my years) is very different in the US .vs. the UK. Among other things, the waivers signed here, at least in Florida, ARE effective. There have been people who have killed themselves diving, the next-of-kin have attempted to pierce commercial dive boat liability releases, and they have failed. There is a whole host of case law on this point, and scuba diving has been effectively designated as an "inherently dangerous" pursuit. In fact, such is drilled into your head during even primary dive training. So the snide quips in that "article" aside, the US (or at least Florida!) appears to actually be a SAFER environment for dive operators than the U.K.
Next, I'm not arguing that there isn't a duty owed if you're someone's dive buddy. There is, but it is not absolute. Again, back to case law, there are a bunch of cases here where one member of a pair has gone off and done something beyond the original dive plan, put themselves at risk by doing so, got bent (or dead), and then tried to come after their buddy, instructor, or the operator. These kinds of suits fail around here too.
(As an only somewhat-dive-related example, if I am on the water in my boat and see you thrashing in the water, clearly in peril, I am required by international - and US - law to assist you. That requirement, however, does not extend to putting my own vessel or complement in peril! That is, if shutting down propulsion to retrieve you would expose my veseel to being thrown against the rocks, I am not required to accept that risk.)
Finally, part of living in the US is that you can be sued for any reason and at any time. The better question is whether you have a prayer in Hades of winning such a suit.
The issue postulated here by you, Alban, is some theory of liability attaching due to my having O2, telling people that I have O2, and not forcibly preventing someone from consuming it who chooses to do so as their own sole, personal choice, and then in fact does do so.
In other words, we're talking not about duty of care but a hypothetical duty of interference.
And again, just to be clear, we're talking about someone who has just regained the surface, is not exhibiting any signs or symptoms of DCS at the present time, but knows that they screwed up in some way.
You are also applying this scenario to a boat full of divers, none of whom is an MD, say much less a hyperbaric physician, and none of whom is acting in a professional capacity (that is, our training such matters is that of a scuba diver, and what we have learned as divers about O2 and its role in removing N2 from the body.)
I don't buy it.
The fact is that by breathing pure O2 on the surface you will increase the rate of N2 departure from your body and lessen the overpressure of N2 within your tissues. This is a scientific fact, and since it is that very same overpressure of N2 that causes DCS, it is axiomatic that having done so you will have lessened the available overpressure to cause a (potential, but not yet occuring) DCS hit. Since the severity of a hit, all other things being equal, is determined by the available overpressure (the degree of supersaturation) of N2 in the body, it is axiomatic that by lessening that supersaturation you are reducing the severity of any hit that you may subsequently suffer, and in fact you may prevent the hit from occuring in the first place IF you can reduce the supersaturation sufficiently prior to the aggregation of those bubbles and the onset of symptoms.
Think about this for a minute.
Let's say that I exceed the NDL and have a 10' ceiling for 5 minutes, on 32% EANx as a consequence. Let's further say that I don't HAVE 5 minutes of gas left, so I surface, having blown off my deco obligation.
Ok. I've now reduced the ambient pressure to the point where statistically I am exposed to a DCS hit. This does not necessarily mean I am going to get bent, but it DOES mean that statistically speaking, I am more likely to get hit than someone who stayed the 5 minutes.
BTW, my computer's beeping at me says that I have three minutes (in the case of my Sunnto) to get BACK to 10! In other words, if I can surface, grab a NEW bottle of gas, and go BACK to 10', I have not violated the computer! (In-water de/re-compression - officially sanctioned by computer manufacturers - anyone?!)
For the sake of argument, let's say I can't (or don't want to) do that, having bought into the proffering of opinions that IWR is so hazardous that it should not be attempted. I get on the boat, knowing that I blew the profile.
I grab the O2 bottle and consume it.
What have I done?
1. I have increased the rate of perfusion of N2 out of my body significantly. I do not know the exact percentage by which I have done so, but it is axiomatic that I have done so. Let's say, for the sake of argument, that I have doubled the rate of perfusion out of my body.
2. Let's further postulate that I am two pressure groups "off the chart" of the SSI tables (which is why I'm at risk of being bent in the first place.) That is, instead of being a "K" diver, I'm a (theoretical) "M" diver (which they don't chart, because that's in a decompression-required range that they don't include in their tables)
Now, the issue at bar becomes "how long does it take for the micronuclei in my body to attract enough additional gas molecules - and grow enough - to cause me to become symptomatic, and can I bleed off supersaturation quickly enough to prevent that from happening", right?
Does doubling (or increasing by "X%", whatever that value of "X" really is) prevent that?
There is no way to know with certainty the answer to that question.
But can we say with any kind of certainty that breathing the O2 will HELP, in other words, such an act will, without fail, provide at least no worse a chance of a hit, and no worse of a hit if you DO get nailed, than you would have if you did nothing?
Absolutely.
THAT is, for me as an individual diver, THE gold standard.
Having already screwed up, which is THE reason that I am at risk of getting hit, I will take every reasonably-available action to attempt to reduce the odds of a hit, and the severity of a hit if I get nailed anyway. I will do so knowing that the original set of acts that placed me at risk of beig bent were my responsibility, and further, as a sentient adult who accepts responsibility for my own actions I am choosing to attempt to mitigate those risks - win, lose or draw.
The ONLY act that I can take ON THE BOAT that will materially change the odds is to grab and breathe the bottle of O2.
Further, by grabbing the bottle I announce to the entire boat that you believe you may be at risk for a hit. Its pretty hard to miss someone toting around an O2 cylinder and demand valve. If anything, this is going to lead to heightened awareness by every other person on that boat for any signs and symptoms of DCS in your person for the duration of the journey - which can only improve the odds of someone other than you detecting such a subsequent condition.
You're going to have to show me something a whole lot more convincing than the general rubric that I can't drive my buddies around in a boat that's about to sink, knowing that it is about to sink, and then get sued when it DOES sink, to make your point here!
In fact, I would argue that for the boat that HAS O2 on board, discouraging people from consuming it who have reason to believe they are at risk of a DCS hit is the irresponsible (and potentially legally risky) act - not the converse.
Mike, the cite you're giving related to DAN is related to people who WERE symptomatic, breathed O2, became NON-symptomatic while doing so and never followed up! THAT is, indeed, a position that DAN takes (and which is, IMHO, quite reasonable) - that once you have signs and symptoms of DCS you CANNOT count on O2 alone to reverse or treat the disease, and that having experienced the symptoms of DCS, you should never delay in seeking treatment, even if breathing O2 gives you relief. We're talking here, however, about someone who is NOT symptomatic, but knows they have blown their profile in some fashion.
First, the law as I have been led to understand it (and IANAL, although I've paid for plenty of legal advice over my years) is very different in the US .vs. the UK. Among other things, the waivers signed here, at least in Florida, ARE effective. There have been people who have killed themselves diving, the next-of-kin have attempted to pierce commercial dive boat liability releases, and they have failed. There is a whole host of case law on this point, and scuba diving has been effectively designated as an "inherently dangerous" pursuit. In fact, such is drilled into your head during even primary dive training. So the snide quips in that "article" aside, the US (or at least Florida!) appears to actually be a SAFER environment for dive operators than the U.K.
Next, I'm not arguing that there isn't a duty owed if you're someone's dive buddy. There is, but it is not absolute. Again, back to case law, there are a bunch of cases here where one member of a pair has gone off and done something beyond the original dive plan, put themselves at risk by doing so, got bent (or dead), and then tried to come after their buddy, instructor, or the operator. These kinds of suits fail around here too.
(As an only somewhat-dive-related example, if I am on the water in my boat and see you thrashing in the water, clearly in peril, I am required by international - and US - law to assist you. That requirement, however, does not extend to putting my own vessel or complement in peril! That is, if shutting down propulsion to retrieve you would expose my veseel to being thrown against the rocks, I am not required to accept that risk.)
Finally, part of living in the US is that you can be sued for any reason and at any time. The better question is whether you have a prayer in Hades of winning such a suit.
The issue postulated here by you, Alban, is some theory of liability attaching due to my having O2, telling people that I have O2, and not forcibly preventing someone from consuming it who chooses to do so as their own sole, personal choice, and then in fact does do so.
In other words, we're talking not about duty of care but a hypothetical duty of interference.
And again, just to be clear, we're talking about someone who has just regained the surface, is not exhibiting any signs or symptoms of DCS at the present time, but knows that they screwed up in some way.
You are also applying this scenario to a boat full of divers, none of whom is an MD, say much less a hyperbaric physician, and none of whom is acting in a professional capacity (that is, our training such matters is that of a scuba diver, and what we have learned as divers about O2 and its role in removing N2 from the body.)
I don't buy it.
The fact is that by breathing pure O2 on the surface you will increase the rate of N2 departure from your body and lessen the overpressure of N2 within your tissues. This is a scientific fact, and since it is that very same overpressure of N2 that causes DCS, it is axiomatic that having done so you will have lessened the available overpressure to cause a (potential, but not yet occuring) DCS hit. Since the severity of a hit, all other things being equal, is determined by the available overpressure (the degree of supersaturation) of N2 in the body, it is axiomatic that by lessening that supersaturation you are reducing the severity of any hit that you may subsequently suffer, and in fact you may prevent the hit from occuring in the first place IF you can reduce the supersaturation sufficiently prior to the aggregation of those bubbles and the onset of symptoms.
Think about this for a minute.
Let's say that I exceed the NDL and have a 10' ceiling for 5 minutes, on 32% EANx as a consequence. Let's further say that I don't HAVE 5 minutes of gas left, so I surface, having blown off my deco obligation.
Ok. I've now reduced the ambient pressure to the point where statistically I am exposed to a DCS hit. This does not necessarily mean I am going to get bent, but it DOES mean that statistically speaking, I am more likely to get hit than someone who stayed the 5 minutes.
BTW, my computer's beeping at me says that I have three minutes (in the case of my Sunnto) to get BACK to 10! In other words, if I can surface, grab a NEW bottle of gas, and go BACK to 10', I have not violated the computer! (In-water de/re-compression - officially sanctioned by computer manufacturers - anyone?!)
For the sake of argument, let's say I can't (or don't want to) do that, having bought into the proffering of opinions that IWR is so hazardous that it should not be attempted. I get on the boat, knowing that I blew the profile.
I grab the O2 bottle and consume it.
What have I done?
1. I have increased the rate of perfusion of N2 out of my body significantly. I do not know the exact percentage by which I have done so, but it is axiomatic that I have done so. Let's say, for the sake of argument, that I have doubled the rate of perfusion out of my body.
2. Let's further postulate that I am two pressure groups "off the chart" of the SSI tables (which is why I'm at risk of being bent in the first place.) That is, instead of being a "K" diver, I'm a (theoretical) "M" diver (which they don't chart, because that's in a decompression-required range that they don't include in their tables)
Now, the issue at bar becomes "how long does it take for the micronuclei in my body to attract enough additional gas molecules - and grow enough - to cause me to become symptomatic, and can I bleed off supersaturation quickly enough to prevent that from happening", right?
Does doubling (or increasing by "X%", whatever that value of "X" really is) prevent that?
There is no way to know with certainty the answer to that question.
But can we say with any kind of certainty that breathing the O2 will HELP, in other words, such an act will, without fail, provide at least no worse a chance of a hit, and no worse of a hit if you DO get nailed, than you would have if you did nothing?
Absolutely.
THAT is, for me as an individual diver, THE gold standard.
Having already screwed up, which is THE reason that I am at risk of getting hit, I will take every reasonably-available action to attempt to reduce the odds of a hit, and the severity of a hit if I get nailed anyway. I will do so knowing that the original set of acts that placed me at risk of beig bent were my responsibility, and further, as a sentient adult who accepts responsibility for my own actions I am choosing to attempt to mitigate those risks - win, lose or draw.
The ONLY act that I can take ON THE BOAT that will materially change the odds is to grab and breathe the bottle of O2.
Further, by grabbing the bottle I announce to the entire boat that you believe you may be at risk for a hit. Its pretty hard to miss someone toting around an O2 cylinder and demand valve. If anything, this is going to lead to heightened awareness by every other person on that boat for any signs and symptoms of DCS in your person for the duration of the journey - which can only improve the odds of someone other than you detecting such a subsequent condition.
You're going to have to show me something a whole lot more convincing than the general rubric that I can't drive my buddies around in a boat that's about to sink, knowing that it is about to sink, and then get sued when it DOES sink, to make your point here!
In fact, I would argue that for the boat that HAS O2 on board, discouraging people from consuming it who have reason to believe they are at risk of a DCS hit is the irresponsible (and potentially legally risky) act - not the converse.
Mike, the cite you're giving related to DAN is related to people who WERE symptomatic, breathed O2, became NON-symptomatic while doing so and never followed up! THAT is, indeed, a position that DAN takes (and which is, IMHO, quite reasonable) - that once you have signs and symptoms of DCS you CANNOT count on O2 alone to reverse or treat the disease, and that having experienced the symptoms of DCS, you should never delay in seeking treatment, even if breathing O2 gives you relief. We're talking here, however, about someone who is NOT symptomatic, but knows they have blown their profile in some fashion.