Walter:
I could not agree more.
Can some explain to me what PPO2 is?
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I could not agree more.
Don Burke
Contributor
jonnythan:Henry's Law isn't exactly BOW material.
Besides, I meant Boyle's and Charles' laws. And you know it
Henry's law is fundamental for understanding gas absorption and it was taught in my SSI OW course back in 1987. In fact, until I was dealing with non-air breathing gasses/mixtures, Dalton's law had little to do with the way I was diving.
I guess the word "all" means something else in your native language.
No, I have no idea how you could think Henry's law wasn't involved.
JustAddWater
Guest
Couldn't Charles Law be applied to the change in tank air pressure due to temperature?
We were taught this in my OW class in reference to "hot fills" and tank storage.
We were taught this in my OW class in reference to "hot fills" and tank storage.
JustAddWater:
We use it more to describe why it is not one of the brightest ideas in the world to use that hot tub on a liveaboard after "taking full advantage" of the four or five dives available to you per day.
One of our instructors had his wife get a case of the "skin bends" this way.
JustAddWater,
"Couldn't Charles Law be applied to the change in tank air pressure due to temperature?"
No. Charles' Law does not deal with pressure/temperature relationships. It deals with volume/temperature relationships. It does relate to a gases in a flexible container such as a balloon.
Amonton's Law is the law that explains the change in tank pressure due to temperature. It is usually and incorrectly taught in SCUBA classes as Charles' Law. I don't know why this is the case, I'd guess an early influential dive instructor made the mistake and it's been passed down through the generations of instructors.
diverbrian,
Your hot tub example actually illustrates Henry's Law, not Charles'.
perpet1.
"Your <sic> right but the members have the same minimum standard"
They do not let their individual standards drop below a common level. That is far different from saying their standards are the same. It is not splitting hairs.
"OK and you are saying what exactly? This is relavant <sic> how? you are arguing the chicken or the egg but it does not really matter."
You were the one who asked what was in error in the article. You didn't narrow the field, you just wanted to know the errors. It isn't relevant to the larger issue, but it does speak to the credibility of the article.
"and that make this statement incorrect how?"
The article is saying YMCA has strict time requirements while PADI has no time requirements. In fact, both sets of standards mention time requirements in much the same manner. This is an instance in which the article disagrees with your assertion that standards are basically the same. The truth of the matter is, in this portion of the standards, while the do have slight differences, they are very small and regarding time requirements, you are correct, the various standards are essentially the same. The article is misleading and incorrect. It's certainly another example of the lack of credibility in this article.
"Besides how is referencing NAUI incorrect here"
The article claims NAUI has one requirement when, in fact, NAUI's requirement is different. By definition, that statement is incorrect.
"I agree totally but in context there was nothing wrong with the statement."
It is misleading, the fact that it is misleading is what is wrong with the statement.
"Couldn't Charles Law be applied to the change in tank air pressure due to temperature?"
No. Charles' Law does not deal with pressure/temperature relationships. It deals with volume/temperature relationships. It does relate to a gases in a flexible container such as a balloon.
Amonton's Law is the law that explains the change in tank pressure due to temperature. It is usually and incorrectly taught in SCUBA classes as Charles' Law. I don't know why this is the case, I'd guess an early influential dive instructor made the mistake and it's been passed down through the generations of instructors.
diverbrian,
Your hot tub example actually illustrates Henry's Law, not Charles'.
perpet1.
"Your <sic> right but the members have the same minimum standard"
They do not let their individual standards drop below a common level. That is far different from saying their standards are the same. It is not splitting hairs.
"OK and you are saying what exactly? This is relavant <sic> how? you are arguing the chicken or the egg but it does not really matter."
You were the one who asked what was in error in the article. You didn't narrow the field, you just wanted to know the errors. It isn't relevant to the larger issue, but it does speak to the credibility of the article.
"and that make this statement incorrect how?"
The article is saying YMCA has strict time requirements while PADI has no time requirements. In fact, both sets of standards mention time requirements in much the same manner. This is an instance in which the article disagrees with your assertion that standards are basically the same. The truth of the matter is, in this portion of the standards, while the do have slight differences, they are very small and regarding time requirements, you are correct, the various standards are essentially the same. The article is misleading and incorrect. It's certainly another example of the lack of credibility in this article.
"Besides how is referencing NAUI incorrect here"
The article claims NAUI has one requirement when, in fact, NAUI's requirement is different. By definition, that statement is incorrect.
"I agree totally but in context there was nothing wrong with the statement."
It is misleading, the fact that it is misleading is what is wrong with the statement.
Walter once bubbled...
All I said was that PP02 is NOT somthing that is useful to any OW student as they aren´t supposed to go deeper than 18 meters (59ft). Making the argument that a lot of OW students do, to me, just reinforces my argument that instructors should spend the time they teach PP02 to teach respect for the boundaries of whatever agency thery´re instructing for. I am NOT advocating a lowering of standards, in fact I´m doing the opposite! Follow standards, or even exceed them by all means, but do NOT do so before you have educated students that will follow them.
You are correct that I am a strong believer in leaving out nonessentials from OW. That you are not...Why don´t you instruct your OW students in tri-mix while you´re at it? (they may have use of that later as well)...
As for starting a new agency. I´m not saying that there aren´t bad PADI courses/instructors etc out there, just as I´m pretty sure that you can say that the same isn´t true of YMCA (and be honest). We were talking about standards and whether pp02 was relevant to OW (at least I was). I said nothing about the relevance of Daltons law (or any other law for that matter). Inference is a fine thing, if used with judgement...
All I said was that PP02 is NOT somthing that is useful to any OW student as they aren´t supposed to go deeper than 18 meters (59ft). Making the argument that a lot of OW students do, to me, just reinforces my argument that instructors should spend the time they teach PP02 to teach respect for the boundaries of whatever agency thery´re instructing for. I am NOT advocating a lowering of standards, in fact I´m doing the opposite! Follow standards, or even exceed them by all means, but do NOT do so before you have educated students that will follow them.
You are correct that I am a strong believer in leaving out nonessentials from OW. That you are not...Why don´t you instruct your OW students in tri-mix while you´re at it? (they may have use of that later as well)...
As for starting a new agency. I´m not saying that there aren´t bad PADI courses/instructors etc out there, just as I´m pretty sure that you can say that the same isn´t true of YMCA (and be honest). We were talking about standards and whether pp02 was relevant to OW (at least I was). I said nothing about the relevance of Daltons law (or any other law for that matter). Inference is a fine thing, if used with judgement...
"All I said was that PP02 is NOT somthing that is useful to any OW student as they aren´t supposed to go deeper than 18 meters (59ft)."
That isn't even close to what you said. You said:
"Saying that you err on the side of caution when giving students more information then <sic> required (or, as some would argue, useless to them). Like others have said before, attention is in finite supply and spending it on things that you do not need for OW-diving is not being cautious! Its quite the opposite, IMHO."
"We were talking about standards and whether pp02 was relevant to OW (at least I was)."
If that was your intention, you did a poor job of it. Besides, I never saw anyone say PPO2 was relevant to OW diving. Inference is a fine thing, if used with judgement. What you said was standards shouldn't contain any material not needed by the OW diver. The problem with that defining what is needed. My opinion is obviously different from yours. The argument that Dalton's Law is not needed implies decompression theory and dive tables are not needed. If you accept that argument, you can eliminate Henry's Law as well. Taking that concept to it's logical conclusion, gives you the bare minimums I outlined.
"Follow standards, or even exceed them by all means, but do NOT do so before you have educated students that will follow them."
I know I don't understand what you mean with that statement. It seems as if you are telling me teach in the future before I teach in the present. Since I know you don't mean that, I have no idea what was in your mind when you typed that sentence.
That isn't even close to what you said. You said:
"Saying that you err on the side of caution when giving students more information then <sic> required (or, as some would argue, useless to them). Like others have said before, attention is in finite supply and spending it on things that you do not need for OW-diving is not being cautious! Its quite the opposite, IMHO."
"We were talking about standards and whether pp02 was relevant to OW (at least I was)."
If that was your intention, you did a poor job of it. Besides, I never saw anyone say PPO2 was relevant to OW diving. Inference is a fine thing, if used with judgement. What you said was standards shouldn't contain any material not needed by the OW diver. The problem with that defining what is needed. My opinion is obviously different from yours. The argument that Dalton's Law is not needed implies decompression theory and dive tables are not needed. If you accept that argument, you can eliminate Henry's Law as well. Taking that concept to it's logical conclusion, gives you the bare minimums I outlined.
"Follow standards, or even exceed them by all means, but do NOT do so before you have educated students that will follow them."
I know I don't understand what you mean with that statement. It seems as if you are telling me teach in the future before I teach in the present. Since I know you don't mean that, I have no idea what was in your mind when you typed that sentence.
Interpreting texts will always be difficult as I think our exchanges have proven to anyone with the patience to go thru them...I thought about quoting myself and you from here to infinity but decided to focus on making my original point...
To summarize: I took exception to your point (as I understood it, and still do) that more facts and formulas in a class = more knowledge. I argue that the opposite might well be true. Sometimes "less is more". If that is the case in your class or not, I do not know, nor have I ever claimed to.
I am simply making the argument that in a class with limited resources (=dives and class time), making sure that the students understand the basics is more important than teaching them how to make calculations (ppo2) that they wont have any use for with their current certification. My feeling is that ppo2 will never be relevant enough to OW (as it is now) for it to be included at expense of repetition of all the other things that you are supposed to learn in that class.
That you took this as an excuse to engage in some PADI bashing (which, to be fair, might not be completely uncalled for) instead of arguing the point I was TRYING to make...well I don´t think I can make that point much clearer than this so I guess we´ll see how you respond...
To summarize: I took exception to your point (as I understood it, and still do) that more facts and formulas in a class = more knowledge. I argue that the opposite might well be true. Sometimes "less is more". If that is the case in your class or not, I do not know, nor have I ever claimed to.
I am simply making the argument that in a class with limited resources (=dives and class time), making sure that the students understand the basics is more important than teaching them how to make calculations (ppo2) that they wont have any use for with their current certification. My feeling is that ppo2 will never be relevant enough to OW (as it is now) for it to be included at expense of repetition of all the other things that you are supposed to learn in that class.
That you took this as an excuse to engage in some PADI bashing (which, to be fair, might not be completely uncalled for) instead of arguing the point I was TRYING to make...well I don´t think I can make that point much clearer than this so I guess we´ll see how you respond...
grazie42,
You made your point about PPO2 clear in this morning's post. Your previous post did not seem to be addressing PPO2. I responded to what you said, not what you intended to say. If I had know what you intended to say, I would have replied to that. I don't believe it is fair to ask me to ignore what you say and respond to what you meant to say. There's no way I can know what you meant to say.
With respect to Dalton's Law and PPO2 in an OW class, I believe it is important to understand the concepts of partial pressure to understand decompression concepts and oxygen toxicity. For this reason, I teach those concepts. I do not believe it is necessary for OW students to be able to calculate PPO2 and I do not teach it.
"you took this as an excuse to engage in some PADI bashing"
It's amazing how I get accused of PADI bashing when I never mention PADI.
You made your point about PPO2 clear in this morning's post. Your previous post did not seem to be addressing PPO2. I responded to what you said, not what you intended to say. If I had know what you intended to say, I would have replied to that. I don't believe it is fair to ask me to ignore what you say and respond to what you meant to say. There's no way I can know what you meant to say.
With respect to Dalton's Law and PPO2 in an OW class, I believe it is important to understand the concepts of partial pressure to understand decompression concepts and oxygen toxicity. For this reason, I teach those concepts. I do not believe it is necessary for OW students to be able to calculate PPO2 and I do not teach it.
"you took this as an excuse to engage in some PADI bashing"
It's amazing how I get accused of PADI bashing when I never mention PADI.
...that believe their OW divers are only safe and are only going to 60 feet? I the years I have been diving I have never seen anyone ever saying anything on a dive about this. If you are safe diving to 30 feet then your next problems with depth are keeping track of how long you can stay and dealing with nitrogen narcosis.
I am suspect of any program that does not recognize how it is being used and adjust of it. If it doesnt then it is only in it for the money and it doesnt have its students best interests in mind.
Truva
I am suspect of any program that does not recognize how it is being used and adjust of it. If it doesnt then it is only in it for the money and it doesnt have its students best interests in mind.
Truva
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