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911_abuser
January 15th, 2004, 07:10 PM
I am confused as to what this is and in what applications it would be used.

archman
January 15th, 2004, 07:12 PM
It's partial pressure oxygen you goof! You DID learn this in basic scuba didn't you?

DeepScuba
January 15th, 2004, 07:28 PM
Goof!!

hehehehheehheh

Do you guys know each other???? This sounds like a quarrel between friends!!!!

If not, this is gonna get juicy REAL quick!!!

Man that's funny.

Uhm, getting back to it, I'm not sure if I learned this in OW.

roturner
January 15th, 2004, 07:31 PM
I am confused as to what this is and in what applications it would be used.

It means "partial pressure of oxygen". It's calculated by multiplying the percentage of O2 in your gas mix by the pressure it's under.

For example, at 33ft you're at 2ata (2x atmospheric pressure). That's 2x 0.21% if you're calculating the PPO2 of air at this depth, so at 33ft air has a PPO2 of .42

It's important because oxygen becomes toxic above 1.6 or so. That means that the maximum operating depth (MOD - something else you'll eventually see here) is determined to be the depth at which you hit the 1.6 PP02 boundary.

If you take a Nitrox class you'll learn more about this too.

hope that helps (or at least more than being called a goof).

R..

AzAtty
January 15th, 2004, 07:34 PM
You probably learned about "Dalton's Law," but the instructor may not have explained it very well or might have said you really wouldn't need to know much about it--besides not to breathe oxygen below a certain depth or not to dive on air below a certain depth. PADI taught the concept back in the 80's when I certified, but I don't see any reference to it in their new book (but I didn't look too hard).

Scubaroo
January 15th, 2004, 07:35 PM
This is explained in a nitrox course - I don't think it gets covered in OW classes. PPO2 is the "partial pressure" of oxygen. Briefly, at the surface, you're breathing 1 ATA of air, 21% oxygen (O2), 79% nitrogen (well approximately anyway). The PPO2 is 0.21. At 33', you are still breathing 21% oxygen if you're diving air, but the ambient pressure is now 2 ATA, so the PPO2 is 0.21 * 2 = 0.42. At 66', your PPO2 is 0.63. It is generally felt that a PPO2 of 1.4 (roughly the equivalent of breathing air at 187') is the safe working maximum PPO2 you should expose yourself to, and a PPO2 of 1.6 is the safe MAXIMUM PPO2 you should expose yourself to (roughly 218' depth), before oxygen toxicity becomes a concern. At these depths however, nitrogen narcosis is probably the limiting factor.

PPO2 becomes of real concern when diving nitrox - say you're breathing a mixture of EAN40, which is 40% oxygen, 60% nitrogen - a PPO2 of 1.6 is as shallow as 99' - which is within the recreational depth limits for air. So by diving a tank of nitrox and treating it like a tank of air, without regard to the PPO2 of the mixture at depth, is a receipe for tragedy.

MikeS
January 15th, 2004, 07:37 PM
I am confused as to what this is and in what applications it would be used.

It's not something easily explained in a post. The best thing to do is to take a Nitrox course where it should be explained. Short of that read Nitrox course ware. In reference to diving, above a certain partial pressure (PP), oxygen (02) becomes toxic and below a certain PP02 you will pass out. But again, this is not an issue diving air at recreational depths.


It's partial pressure oxygen you goof! You DID learn this in basic scuba didn't you?

I don’t think that it’s covered in OW training as it’s not a concern diving air at recreational depths.

Mike

Walter
January 15th, 2004, 07:43 PM
"I don't think it gets covered in OW classes."

"I don’t think that it’s covered in OW training"

It is covered in YMCA OW courses.

Scubaroo
January 15th, 2004, 08:00 PM
Unfortunately not everyone has access to YMCA courses Walter :)

matt_unique
January 15th, 2004, 08:13 PM
Yeah PP02 is the partial pressure of 0xygen. Oxygen becomes toxic at certain depths at certain mixes. This PP02 number provides a way to measure that potential for toxicity. When the PP02 reaches 1.4 or above there are potential hazzards including CNS toxicity (Central Nervous System). This could "ruin you whole day" because the worst possible outcome is passing out without any other symptom.

You will first learn about this in a Nitrox course. If you are breathing compressed air you don't have to worry about PP02 or CNS toxicity until you are approaching 218 feet.

--Matt

DA Aquamaster
January 15th, 2004, 08:31 PM
It's important because oxygen becomes toxic above 1.6 or so. That means that the maximum operating depth (MOD - something else you'll eventually see here) is determined to be the depth at which you hit the 1.6 PP02 boundary.

Roturner is correct but there is a little more to it and discussing the maximum PPO2 that is considered acceptable is normally a good way to start an argument.

PPO2's far lower than 1.6 or 1.4 are still toxic given enough time and PPO2's well above 1.6 can be tolerated for short times. The specific times are where it gets interesting as they can vary from diver to diver, from day to day, with workload and with other confounding variables such as elevated CO2 levels and the amount of nitrogen in the mix.

A PPO2 of 1.6 is considered the acceptable max for sport diving and many people feel the more conservative limit of 1.4 is better for portions of the dive where you are exerting yourself. But as a rule, the higher the PPO2, the shorter the period of time you can be exposed to it without potential problems.

Short term problems with high PPO2 include central nervous sysytem problems up to and including convulsions where the diver is likely to lose his reg and then drown. Longer term exposures to high 02 levels can cause pulminary problems due to oxygen at high partial pressures damaging lung tissue. (This can even occur with 100% O2 at 1 ATA given enough time.) Really long term problems can also occur such as bone necrosis but this is not an issue in sport diving.

Wendigo
January 15th, 2004, 09:47 PM
Walter is 100% correct. I know it is covered in YMCA OW certification because we teach it in every single class I have ever attended, taught, or sat in on.

Not to piss anyone off, but I did let two of my friends go through other agencies for their OW training so they could finish faster and go on a dive trip with me (this ended up a mistake on my part). One went through PADI and the other through SSI. I hate to say it, neither one knew anything about Daltons Law or partial pressures the day after they finished.

They both are very intelligent people with plenty of common sense, but neither one knew how to properly use dive table after going through the class. When I asked them why they didnt cover this more in depth in the class, I got a response that the LDS's instructors basically didnt think it was necessary since they would end up using a computer anyway (that they'd sell them I'm sure). Now that is asinine to assume that. It turns out that I ended up totally re-training both on the trip which sucked for me (paying for my mistake of sending them to other agencies). This was two competing shops around Nashville that basically skimmed dive tables.

Thank god they are diving with me, otherwise they would have made some very unsafe divers (no cockiness intended).

All right everybody, you can start your flaming now.....

perpet1
January 15th, 2004, 09:52 PM
"I don't think it gets covered in OW classes."

"I don’t think that it’s covered in OW training"

It is covered in YMCA OW courses.

Required per standard or is it just something you present? The WRSTC (of which YMCA is a member) is not clear. The just say an understanding of pressure/gas laws.

http://www.wrstc.com/downloads/Open%20Water%20Certification.pdf

DeepScuba
January 15th, 2004, 09:56 PM
I guess Wendigo it was a fault of theirs OR the instructor, as Dalton's law and tables are obviously taught in PADI. Partial Pressures, in as much it coincides with Dalton, wasn't taught as such RE Oxtox etc in our OW. Of course it's standard in Nitrox when it actually starts to become relevant.

I don't see too many people toxing out @ 60ft on air, which is to say, teaching it (PP's) in OW isn't really necessary.

Wendigo
January 15th, 2004, 09:57 PM
Well, all I can say is that I have been in these shops and if they did skim the info *they* deem not necessary, it would not suprise me. I have been appalled at some of the carelessness of several LDSs. I must be in the minority in thinking having an overly cautious new diver is the only way to train.

Oh and perpet1, The newest version of the YMCA student book has partial pressures and all the laws used for SCUBA in it, and we cover every page of that manual.

It is also quite a nice reference book for me. We just started using it not long ago. It is also a requirement on the part of the instructor. I basically follow a lesson plan that is revised every so often by the agency.

You are allowed freedom to teach in a different order than is planned out, but you must cover everything in it.

IndigoBlue
January 15th, 2004, 10:00 PM
Goof!!

hehehehheehheh

Do you guys know each other???? This sounds like a quarrel between friends!!!!

If not, this is gonna get juicy REAL quick!!!

Man that's funny.

Uhm, getting back to it, I'm not sure if I learned this in OW.

When I took basic open water, Dalton's Law had not been invented yet. Neither had nitrox. Back then, the main thing you learned was Martini's Law, of 1 martini per every 50 ft.

Back in those days, there were no SPGs either, and everyone had J valves, or else they used their watch carefully.

Today we teach Dalton's Law in basic open water. But I swear the students' eyes glaze over at the mention of it. Since they are not diving nitrox, they cannot relate very well.

chrpai
January 15th, 2004, 10:06 PM
It's partial pressure oxygen you goof! You DID learn this in basic scuba didn't you?

I'm afraid partial pressure is not tought at the OW by many agencies these days. There is often mention of oxygen toxicty on air at depths beyond recreational limits and thats it.

Take a mixed gas class and you'll learn it though.

IndigoBlue
January 15th, 2004, 10:06 PM
It means "partial pressure of oxygen". It's calculated by multiplying the percentage of O2 in your gas mix by the pressure it's under.

For example, at 33ft you're at 2ata (2x atmospheric pressure). That's 2x 0.21% if you're calculating the PPO2 of air at this depth, so at 33ft air has a PPO2 of .42

It's important because oxygen becomes toxic above 1.6 or so. That means that the maximum operating depth (MOD - something else you'll eventually see here) is determined to be the depth at which you hit the 1.6 PP02 boundary.

If you take a Nitrox class you'll learn more about this too.

hope that helps (or at least more than being called a goof).

R..

Long before you have to worry about air in your tanks becoming toxic at or above 1.6 ATAs ppO2, you will have run into the problem of the N2 in your air becoming extremely intoxicating, starting at 130 ft, and getting progressively worse, until you become a zombie around .... hmmm ... should I tell him/her?

ppO2 is a major limitation whenever you are diving nitrox. When you take a nitrox class, hopefully they will teach you about it then.

MIX.......MOD....ppO2

EAN32...111ft...1.4ATAs

EAN36...95ft.....1.4ATAs

EAN40...83ft.....1.4ATAs

EAN50... ahhh well thats ADvanced Nitrox

Wendigo
January 15th, 2004, 10:25 PM
Do any of you really think that it is a good idea to skim these lessons just because it isn't absolutely critical at OW depths?

I truly hope not. Having more information can do nothing to harm a diver, however it can be a great detriment to have too little. Besides, if they do go on to nitrox classes, they will be just that much further ahead.

Walter
January 15th, 2004, 10:26 PM
"Required per standard or is it just something you present?"

Required per standard. How do you explain the theory of decompression without discussing Dalton's Law of partial pressures?

Wendigo
January 15th, 2004, 10:27 PM
Exactly.

IndigoBlue
January 15th, 2004, 10:41 PM
Do any of you really think that it is a good idea to skim these lessons just because it isn't absolutely critical at OW depths?

I truly hope not. Having more information can do nothing to harm a diver, however it can be a great detriment to have too little. Besides, if they do go on to nitrox classes, they will be just that much further ahead.

The student's eyes truly glaze over from the information overload, Wendigo.

The text has a photo of a bottle of tonic water fizzing. That is normally the starting point for the discussion of the theory of decompression, Walter. They can relate to that.

MikeS
January 15th, 2004, 10:51 PM
It is covered in YMCA OW courses.

Why? What berring does it have on diving with air at recreational depths?

chrpai
January 15th, 2004, 10:55 PM
Why? What berring does it have on diving with air at recreational depths?

Because know it alls have to criticize the agencies. They refuse to acknowledge that basic OW divers:

a) breath air with a static fo2 and no2
b) ppo2 thresholds are not a concern 0 to 60fsw
c) narcosis is not a concern at 0 to 60fsw ( course I'm sure someone will say they breat rec triox at 60fsw )
d) can simply be told the deeper you go the less time you can stay
e) can be trained to follow a table with certain procedures/rules without neededing to fully understand the theory behind it
f) many just want to go have a fun time and not play arm chair OWSI on the internet

perpet1
January 15th, 2004, 11:11 PM
"Required per standard or is it just something you present?"

Required per standard. How do you explain the theory of decompression without discussing Dalton's Law of partial pressures?

Not what I asked. I asked is it required by the YMCA open water standard. I read the source of the YMCA standards and it is not clear the degree to whitch you woulod discuss decompression.

WRSTC quote

4.3 Physics of Diving. Open water level information on the physical principles of matter and their application to diving activities and hazards.
(1) Sound
(2) Light
(3) Buoyancy
(4) Pressure/gas laws
(5) Temperature

This is the extent of the guidance. Does the YMCA standard specify that you talk about daltons pressure law for open water certification? Some would argue that diving on air within the recreational limits that it would PPO2 would not be a factor. I am guessing this is why the WRSTC is vague in this area.

That said it is clear that the agency and or instructor can teach beyond the standard. It sounds to me that you are and I commend you for it but lets be clear as to what the standard says (not just the way you think it should be).

But it is all good.

Pete

pt40fathoms
January 15th, 2004, 11:14 PM
I've seen more and more questions being posed on this board that makes me wonder if the person asking the question is in fact a diver. If they are not a diver, I have no problem with that, or them asking questions about diving. Hopefully their curiosity will lead them to pursue diving as a hobby. If they are a diver, and have posed a question that is so basic that they make it clear they were cheated out of a proper education. Then we should try to get them in touch with a good instructor for some catch up tutoring. The question posed in this thread however is not of such a basic nature, and I'm glad to see it was answered correctly by several of you.

We may all wish that an OW class contained everything and anything that is associated with diving, but that is just not realistic. That’s what specialty courses are for. Just as it is not realistic to expect someone who has just passed an OW course to be perfect in trim and buoyancy control. That’s what practice and diving with an experienced diver as a buddy is for.

DeepScuba
January 16th, 2004, 12:33 AM
I'm with Indigo on this one.

Perhaps Wendigo, you've forgotten that these newbs, for want of a better name are just learning how to scuba, it's why it's called Basic OW.

The only thing they truly understand is "deep water hurts my ears" at this stage.

The eyes glaze because it isn't yet real to them. They don't make the connection..it's why they're called NEW, It's why they are trained to 60ft only.

PP's are the least of thier worries at 60ft.

It won't be long from that point before it becomes relevant, but not at OW.

Hell, even NOW I don't recall ANY definitions, be it Dalton, or any other old long dead fart that made math and physics such a pain in the a$$.

I seem to fully understand just about anything in scuba as it pertains to PP's, ATA's, Best mix, EAD, END and any other related crap you can throw at me.

But when I was a simple OW student, it was irrelevant to me just learning how to dive.......ow my ear, ow my ear...........look at the pretty fish.........hey this is cool, Ooops broke that hunk of coral. Do it again after 1hr SI.

That's all most OW's know to put it simply.

pt40's got it too, read his last paragraph above.

Wendigo
January 16th, 2004, 01:04 AM
Dont get me wrong, I do see you guys point. That doesn't change the fact that more information can't hurt. That is part of our philosophy.

As far as "eyes glazing over" , well that is a real concern with the amount of time we spend with students in YMCA courses. A good instructor gives lots of breaks and can tell when students are zoning out.

YMCA doesnt see any of these as too in depth for basic OW certification:
(1) Sound
(2) Light
(3) Buoyancy
(4) Pressure/gas laws
(5) Temperature
I'd say we spend approx. 2 hours going through the basics of these priciples, and probably another 2 hours on the pressure/gas laws lesson. The students take home their books. They also take home handouts and problems. When they come back to class, they have studied the material on their own and we answer any questions they came up with.

I know some of you guys think this is way too much to ask, but that is the way it has always been with the YMCA program. From what I understand the NAUI program is pretty comprehensive too.

I am not trying to say that PADI and SSI are creating unqualified OW divers at all. However, I am saying that the students coming out of our YMCA OW program locally are some of the best OW level divers you will ever meet. I'll bet they would amaze some of you with their understanding.

We also work on the buoyancy control in the pool for a pretty good while. And dont get me started on buddy breathing being a "liability"

911_abuser
January 16th, 2004, 01:49 AM
Thank you all for the explanations regarding PPo2. I now understand its purpose regarding diving somewhat and do intend on taking a Nitrox class as soon as I can. And no PPO2 was not taught in my OW class. Dalton yes, PPO2 no.

Now in part 2 of my question...

Can someone compare 2 dives for me. I am interested in diving the Captain Dan wreck here in Fort Lauderdale. At 110 ft ( no ndl chart to look at ) I believe I can stay down for around 15 minutes, including safety stop. How would such a dive compare with NITROX?

archman
January 16th, 2004, 03:11 AM
I got my basic OW through NASDS, and that's where my instructor brought it up. There was a great deal of other stuff he also talked about, ranging from U.S. Navy dive tables to x-rated underwater activities. He also referrred to oxygen as "oxygent."

I'm sure this man is now dead somewhere. And then NASDS merged into SSI. Interesting coincindence...

roturner
January 16th, 2004, 05:16 AM
Thank you all for the explanations regarding PPo2. I now understand its purpose regarding diving somewhat and do intend on taking a Nitrox class as soon as I can. And no PPO2 was not taught in my OW class. Dalton yes, PPO2 no.

Now in part 2 of my question...

Can someone compare 2 dives for me. I am interested in diving the Captain Dan wreck here in Fort Lauderdale. At 110 ft ( no ndl chart to look at ) I believe I can stay down for around 15 minutes, including safety stop. How would such a dive compare with NITROX?

You'll get 5 minutes longer on the bottom with EAN32.

R..

chrpai
January 16th, 2004, 09:01 AM
Thank you all for the explanations regarding PPo2. I now understand its purpose regarding diving somewhat and do intend on taking a Nitrox class as soon as I can. And no PPO2 was not taught in my OW class. Dalton yes, PPO2 no.

Now in part 2 of my question...

Can someone compare 2 dives for me. I am interested in diving the Captain Dan wreck here in Fort Lauderdale. At 110 ft ( no ndl chart to look at ) I believe I can stay down for around 15 minutes, including safety stop. How would such a dive compare with NITROX?

Planning the dive to not exceed PPO2 of 1.4 you could dive 110f on 32% Nitrox. Using the formula

=(((1-0.32)/0.79)*(100+33))-33

You find the equivilant air depth is 81.48'.

There are many tables/computers out there, so lets look at PADI.

PADI AIR RDP 110' = 16 minutes NDL ( not including ascent and safety stop )
PADI AIR RDP 90' (EAD rounded deeper) = 25 minutes NDL ( not inc again)
PADI 32% RDP 110' = 25 minutes.

Suunto Mosquito AIR 110' = 13 minutes NDL
Suunto Mosquito 32% 110' = 21 mintutes NDL

So you see generally 8 or 9 minutes more bottom time. The person who said its 5 minutes must be doing that '5 minute averaging' method or something that I keep hearing about.
So generally you could dive that wreck ( gas management permitted ) 9 minutes more then air.

But you really need to take a class to understand all the gotchas.

Groundhog246
January 16th, 2004, 09:50 AM
Dont get me wrong, I do see you guys point. That doesn't change the fact that more information can't hurt. That is part of our philosophy.

As far as "eyes glazing over" , well that is a real concern with the amount of time we spend with students in YMCA courses. A good instructor gives lots of breaks and can tell when students are zoning out.
The LDS I use certifies with NAUI and a smaller lesser known. They use the YMCA manual as they feel it's one of the most complete and we learned gas laws and partial pressures. They also stress the importance of buoyancy control. They also still teach buddy breathing, partly to offer yet another option in an emergency, but also because it builds comfort in the water. If you get comfortable passing a reg back and forth, you get a lot of practice puttting a reg back in your mouth and purging. We had to do a lap around the pool buddy breathing with no mask. After that, having someone kick your reg out of your mouth or your mask off is no biggy.
I think the biggest difference is going to class/pool once a week with study in between allowing time to absorb information versus a weekend of classroom/pool sessions where you're trying to absorb too much too fast. Thus they pare it down to what is deemed most essential.

cornfed
January 16th, 2004, 09:53 AM
When I took basic open water, Dalton's Law had not been invented yet. Had the earth's crust had a chance to cool yet? wink

Walter
January 16th, 2004, 10:00 AM
perpet1,

"Not what I asked."

Yes, it is. I answered your question exactly.

You asked, "Required per standard or is it just something you present?"

I answered, "Required per standard."

YMCA requires covering the gas laws. Those include Boyle's, Amonton's, Henry's and Dalton's.

IndigoBlue,

"The student's eyes truly glaze over from the information overload"

Perhaps it's not from information overload, perhaps it's from poor presentation?

MikeS,

"Why? What berring does it have on diving with air at recreational depths?"

It is directly related to decompression status.

pt40fathoms,

"We may all wish that an OW class contained everything and anything that is associated with diving"

That's not necessary nor is it desired.

dbulmer
January 16th, 2004, 11:19 AM
Walter,
what is Amonton? You've got me stumped there.

Walter
January 16th, 2004, 11:59 AM
That is the law that explains pressure/temperature relationships.

cornfed
January 16th, 2004, 12:03 PM
That is the law that explains pressure/temperature relationships.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/gaslaws3.html#amonton

Wendy
January 16th, 2004, 02:26 PM
Thank you all for the explanations regarding PPo2. I now understand its purpose regarding diving somewhat and do intend on taking a Nitrox class as soon as I can. And no PPO2 was not taught in my OW class. Dalton yes, PPO2 no.

Now in part 2 of my question...

Can someone compare 2 dives for me. I am interested in diving the Captain Dan wreck here in Fort Lauderdale. At 110 ft ( no ndl chart to look at ) I believe I can stay down for around 15 minutes, including safety stop. How would such a dive compare with NITROX?


The 110' is in the sand, so I doubt that you will be spending much if any time at that depth as most of your dive time will be on the deck, which is at a higher depth.

dbulmer
January 16th, 2004, 03:18 PM
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/gaslaws3.html#amonton

Cornfed,Walter

Thank you - off to do some reading.

DeepScuba
January 16th, 2004, 04:24 PM
Amonton!!!

I thought he was talking about Chinese soup!!!

heheh, well it's nice info and all, but hardly very useful for OW to 60ft.

They really have their hands full just diving. Abusing thier minds with next to useless info AT THAT POINT OF TIME IN THEIR DIVING is exactly why some "newbs" have a hard time remembering the important theory as it pertains to Basic OW......tables etc.

You're right, some things are not required, necessary or desired.

I truly have no idea of the specifics of Amonton (I did learn it, but it was so irrelevant in REALITY, my short term memory doesn't retain fairly useless data) beyond that it's not a REAL issue to any diving you do.

Yes I would love to impress my friends, divers and non, of my wit and deep understanding of all that is Amonton, but alas it would be Cliff Claven material. (Cheers).

Good at parties though.


It impresses the "newbs". Makes them think you know what you're doing!


Gone for Wonton.........

DS

DeepScuba
January 16th, 2004, 04:36 PM
911 Abuser:

Using EAN32 and EAD of 90ft

A scan of several tables (No deco, Mod USN, Buhlmann Sea level, DCIEM) gives from 20 to 25 minutes NDL.

Spectre
January 16th, 2004, 04:41 PM
The 110' is in the sand, so I doubt that you will be spending much if any time at that depth as most of your dive time will be on the deck, which is at a higher depth.

Depends on how your planning it. Typical tables'll end up being 110. I stuck to the deck and maxed at 102.

timhernandez
January 16th, 2004, 05:09 PM
I was taught PP02 and Dalton, Boyle, the effects of water on light, sound,etc. in my open water class in 2002.
It was an SDI class and the instructor did a very good job teaching this material and, making sure his students 'got it'.

We also learned, and practiced buddy breathing in both open and closed environments along with many other skills (like trim and bouyancy,etc).

After lurking and reading these boards for awhile, and seeing, hearing other talk about their training and experieces, I am very pleased with the training my son and I got from SDI.

-Tim

truva
January 16th, 2004, 05:23 PM
Only having attended the YMCA OW class, I have a couple of things I’d like to add here.

They did indeed cover oxygen toxicity, nitrogen narcosis and went over some of the other gas mixes and why you’d choose to use one or the other. In my opinion if you are not letting students know this to some level you are doing them no service.

What that YMCA class gave me was information I needed to learn how to dive safely. I knew the things I needed to work on and I knew what I didn’t know, I cannot stress the safety factor in that. You are not going to make a competent diver in any short class like that but you can supply someone with enough information and knowledge to go out and become one.

I see where several folks mention 60 feet, what does 60 feet have to do with OW?

Truva

RiverRat
January 16th, 2004, 05:24 PM
I'd like to comment here, just my 2 cents....
I'm actually glad I decided to go the OW directly to AOW/Nitrox route with training.
I could almost recommend the Nitrox class to new divers even if they don't plan on diving it right away. It really opened up my eyes to what goes on with our bodies and different (air) gas mixes at depth. For my first dives outside of training dives I booked a trip to G. Cayman. Even though I did a "deep" dive to 60fsw in AOW training one could argue that I should not have been doing 100fsw profiles out in Cayman but that's how they dive out there and that's what I dove. I was impressed however when a buddy team with us set their limit to 60fsw. They weren't comfortable diving that deep and chose to stay at 60. I had a great buddy out there and did feel comfortable, so I chose to go deep. I learned alot about diving on that trip. I'm still pumped about those dives. I guess what I'm trying to say is that for some divers too much info right away may not be good, but for others it may be best to dig right in and go for it. The dive profiles out there took me right to the edge of my MOD on EANx32. Trust me, I had my alarms set on my Vyper. May have annoyed some divers but kept me alert on the deep dives. Now if I was only diving air the MOD would not have been as critical but being as we were diving on walls with essentially "no bottom" it was nice have some of this more advanced training in my head in case of an unforseen disaster.

perpet1
January 16th, 2004, 06:40 PM
Because know it alls have to criticize the agencies. They refuse to acknowledge that basic OW divers:

f) many just want to go have a fun time and not play arm chair OWSI on the internet

Well a lot of the OWSI's are really OWSI's and know the true requirements. I am sure Walter is an incredible Instructor and I would like to take a class from him someday because he seems to really care.

The general discussion as I see it is, is the idea of PPO2 (daltons pressure law) required knowledge for open water students.

Walter thinks it is and that is fine because there is nothing wrong with presenting extra info during a class. I assure you that most divers, for the other reasons you sited and because it is not required in most Open Water standards, do not think PPO2 is required knowledge of an open water student.

Now this is going to raise some issues because there are those that believe that somone should be all knowing prior to setting foot in the water and that the masses are clueless and have no business diving. I just say to them that even they did not know a fraction of what they know today when they started and everyone has to start someplace.

Groundhog246
January 16th, 2004, 06:52 PM
Even though I did a "deep" dive to 60fsw in AOW training one could argue that I should not have been doing 100fsw profiles out in Cayman but that's how they dive out there and that's what I dove.

Not sure how they call 60fsw a "deep" dive. We did 55ffw in our OW certifying dives. Did just shy of 100ffw in AOW. Plan called for getting you deep enough to be narced and skills to let you understand you were narced. No way you got that "lesson" at 60 feet. My LDS also wants you to do 15 to 20 post OW dives and get your buoyancy skills established, before you do AOW. It's hard to do a good compass course if you're still trying to get properly neutral, not to mention the task loading of a night dive.

Walter
January 16th, 2004, 06:55 PM
It's all about what is really necessary to dive safely. There are differing opinions on this and it probably always will be this way. It's possible to cut even more from courses and still allow people to dive safely under perfect conditions. Since I can't promise conditions will always be perfect, I'd rather err on the side of caution and provide more knowledge and skills so my divers will be better prepared for the unexpected.

You could get by under perfect conditions by teaching them to never hold their breath, dive no deeper than 30 feet, use air only, clear a small amount of water from their masks, use a flutter kick (don't worry about technique), ascend no faster than 1 ft every 2 seconds, how to come close to neutral buoyancy by adding and venting air to their BC and start to the surface with at least 300 PSI. I can teach that class in 15 - 30 minutes. As long as nothing ever goes wrong and they stay within the limits, I've set, they'll be fine.

Walter
January 16th, 2004, 06:59 PM
"Did just shy of 100ffw in AOW. Plan called for getting you deep enough to be narced and skills to let you understand you were narced. No way you got that "lesson" at 60 feet."

Actually, a recent study by the Naval Medical Institute in Croatia showed impaired psychomotor testing not only at the generally accepted depth of 4 bars (~99 ft), but also at 2 & 3 bars. The order in which the dives were performed made no difference.

archman
January 16th, 2004, 07:03 PM
I believe NAUI characterizes deep dives starting at 60 or 65 feet. As for using a deep dive in order to "get narced," I find that highly objectionable, and it certainly has not been a component to any dive instruction I have received or taught. I think the Navy makes it part of their program, but that's it.

From what I recall narcosis effects vary from person to person just like DCI, and can occur at any depth (the effects are simply known to increase with depth). The recent results quoted from the Croatian study would be the first substantial thing I've yet heard, but I'd like to know what the details of their tested personnel (age, demographic, physical condition, etc.). In any event I would be very loathe to take a class down deep for the purpose of "learning them" the pitfalls of narcosis. I could just see the lawyers swarming in if an accident happened. You'd need some super hefty waivers and Johnny Cochrane.

divemed06
January 16th, 2004, 07:04 PM
Cutting corners....it works for some students and not for others. When I took my Rescue Course, I was hoping to have a chance to practice numerous emergency situations. Unfortunately, the instructor only did the absolute minimum to cover the course requirement. Most of the other students were happy because they got the card in a relatively short period of time. I on the other hand would have enjoyed doing 20, 30 or even 40 situations instead of the 6 or 7 we did... I guess that might be the difference between someone who wants to take a course and someone who wants to learn...no better no worse, just different interests I guess.

DeepScuba
January 16th, 2004, 07:11 PM
Truva

60ft is the "depth limit" (official??) of a PADI OW diver.

Man you'd think narcosis was "Real Bad" at 30-40ft the way people and agencies talk nowadays.

Hey I'm all for limitting Narcosis, but c'mon. To even waste time looking a narcosis at 30 ft is, uhm,.........a waste of time.

Ditto for 80-100ft. We dive in $hit (literally) and I don't see too many "Royally Narced" people.

What's wrong with a slight buzz, perceived or real?

Shoot, some think I'm narced at 1 ATA!!!!



Flame away......but how many regularly feel ANYTHING worth noting on an 80-100ft dive?

I've done MAYBE 25-30 dives this year less than 100ft. The rest have all been regularly 115 to 130 (all air) and several upwards to 200ft, and I feel I am more susceptible to narcosis than the average person.

jonnythan
January 16th, 2004, 07:19 PM
The student's eyes truly glaze over from the information overload, Wendigo.

The text has a photo of a bottle of tonic water fizzing. That is normally the starting point for the discussion of the theory of decompression, Walter. They can relate to that.

Maybe it's because you simply assume your divers are complete imbeciles who never made it to 8th grade science.

My instructor was a pretty bright guy, and he presented all the gas laws to my (SSI) class in a clear way. The few people in my class who didn't already have a good understanding of the physics involved learned it quickly.. probably because Brian (my instructor) didn't assume we were dopes who can't relate to anything but a bottle of soda.

IndigoBlue
January 16th, 2004, 07:28 PM
Maybe it's because you simply assume your divers are complete imbeciles who never made it to 8th grade science.
.

Jonnythan I do present the Daltons Law material, and ppO2 and ppN2 materials.

The main reason is to give them an understanding of their depth limits.

I will teach them they are OK as new divers to dive to 50 ft, and that they should not dive deeper for awhile. Then I show them what happens when they dive deeper.

I recomend EANx for 50 to 100 ft. In our store, the EANx is usually a part of AOW, together with deeper diving to 100 ft, night diving, and advanced navigation.

I will give them the NOAA postulated ppO2 of 1.4 for diving, and show them how to compute it.

I lose most of them, at that point. Its not on the test either for basic O/W.

They always give me the same look of "why are you telling us this when we don't 'need' to know it?"

jonnythan
January 16th, 2004, 07:32 PM
I will teach them they are OK as new divers to dive to 50 ft, and that they should not dive deeper for awhile. Then I show them what happens when they dive deeper.

What happens when they dive deeper?


I will give them the NOAA postulated ppO2 of 1.4 for diving, and show them how to compute it.

Why show them how to compute it if they're not going to be using it?

Wendigo
January 16th, 2004, 07:38 PM
As Walter said, "I'd rather err on the side of caution and provide more knowledge and skills so my divers will be better prepared for the unexpected."

I couldnt agree more. Being is prepared for the unexpected means knowing what could happen as a result of decisions you make under the water. I dont understand how anyone on the this board could say that less inforamtion is a good thing, at any cert. level.

jonnythan -
Why show them how to compute it if they're not going to be using it?
That has to be one of the most dangerous attitiudes concerning diving I have ever heard.

There's not a lot that anyone is going to say that convinces me that skipping or skimming fundamentals is a good idea. It may save time, but not divers.

IndigoBlue
January 16th, 2004, 07:51 PM
As Walter said, "I'd rather err on the side of caution and provide more knowledge and skills so my divers will be better prepared for the unexpected."

I couldnt agree more. Being is prepared for the unexpected means knowing what could happen as a result of decisions you make under the water. I dont understand how anyone on the this board could say that less inforamtion is a good thing, at any cert. level.
.

When we finish physics and they understand P = D/33 +1 and PO2 = FO2 x P then I will give them a comprehensive diagram of diving depths and gas choices.

0 to 50 ft is air

50 to 100 ft is EANx

100 to 150 ft is EANx or Helitrox

150 to 185 ft is normoxic TMX

185 on down is hypoxic TMX

PO2 is an issue beyond 50 ft on EANx, and I show them the calculations.

PN2 is an issue deeper than 100 ft depth, and I show them the calculations.

When I tell them "this is not on your test, by the way" I lose every one of them on the calculations. The discussion mostly just helps them understand why they should stay shallower than 50 ft while they are basic O/W divers.

grazie42
January 16th, 2004, 07:57 PM
Saying that you err on the side of caution when giving students more information then 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. These things will be taught as they become relevant to the kind of dives you are supposed to do...some might argue that new divers dont always follow these guidelines. To that I say: Spend more time in class and elsewhere teaching them to respect the guidelines! I actually think that that kind of information incourages new divers to feel that they are qualified to dive beyond limits as they "already know all about it"...

Just my 2 cents, feel free to disagree...

DeepScuba
January 16th, 2004, 08:02 PM
heehehhe

When the poop is hitting the fan...... Amonton.......isn't gonna save me.

And it don't matter HOW I re-jig his formula!

hehehheh

Save the info for when it becomes relevant. What's the PO2 of air at 60ft?

We have been speaking OW diver all along, I think this is still the parameter.

Show ehm the can of soda, They're learning to dive for the first time, remember?

I'd sooner see emphasis on the more basic of things.

Basic I say?? Ask MHK what's lacking in Basic OW.

IndigoBlue
January 16th, 2004, 08:04 PM
Saying that you err on the side of caution when giving students more information then 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. These things will be taught as they become relevant to the kind of dives you are supposed to do...some might argue that new divers dont always follow these guidelines. To that I say: Spend more time in class and elsewhere teaching them to respect the guidelines! I actually think that that kind of information incourages new divers to feel that they are qualified to dive beyond limits as they "already know all about it"...

Just my 2 cents, feel free to disagree...

YOU are absolutely right Grazie.

The instructor needs to stay focused and the material must flow.

DeepScuba
January 16th, 2004, 08:10 PM
I've had more than one discussion with an Instructor (I am not) with the safety of taking brand new, 7 dive old OW students to a 110ft, 39 degree, dark-a$$ dive.

They can't even dive in 30ft of water and we're sticking them in 110 ft of dark, free-flow prone, disorienting cold-a$$ water?

Giving "newbs" this much faith, and worse, the "Idea" of them being smarter/better than they are is arguably NOT helping them.

Grazie42, well said. My thoughts exactly.

Unfortunately, keep ehm dumb until they can walk. Give them time to develop the basics.

RiverRat
January 16th, 2004, 08:57 PM
Not sure how they call 60fsw a "deep" dive. We did 55ffw in our OW certifying dives. Did just shy of 100ffw in AOW. Plan called for getting you deep enough to be narced and skills to let you understand you were narced. No way you got that "lesson" at 60 feet.

Hey Groundhog246,
Yes, for PADI AOW's deep dive it's minimum 60 ft. Of course that was max depth of the quarry I trained in :-) We did the math problem on land and at depth. Yes, it was much slower, but not from nitrogen, from 50 degree water, pitch black vis, gloves etc. Even though I didn't get to feel being narced I certainly learned my share of skills related to cold, no vis, disorientation etc. I guess it depends on where you train and what facilities they have.



My LDS also wants you to do 15 to 20 post OW dives and get your buoyancy skills established, before you do AOW. It's hard to do a good compass course if you're still trying to get properly neutral, not to mention the task loading of a night dive

You have a good point here. I just wanted to get more dives in so for me it worked out good that I went right into AOW (and for the LDS' pocketbook too, not that I'm complaining :-) I had HORRIBLE trim and buoyancy control and the Peak Performance Dive was really a waste. The night dive went well.
The NAV dive was stressfull, I burned a ton of air hauling all that lead around!
Trim and Buoyancy control was not really stressed enough. There is another thread out there where I mention that. All in all though those dives made me more confident. After help from many of you on the board I was able build a killer BP/W setup and learned what neutral buoyancy is all about. There may have been a few bumps in the road getting to where I'm at now but it all fell together and I've still got so much more to learn. This sport can be truly mind boggling at times, so much to it. I'm hooked :-)

Walter
January 16th, 2004, 10:17 PM
grazie42,

It's because most people agree with you and would rather take a class with low standards that those classes are the most popular. I believe it will always be that way. In fact, if some agency would start offering the 30 min class I outlined earlier, it would soon surpass PADI as the largest certification agency in the world. Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.

captain
January 16th, 2004, 11:50 PM
I don't know how old Indioblue is but I went through YMCA scuba in 1970 at the ripe old age of 26 and Dalton's law had been invented some time before that. That scuba course was like boot camp. You learned it or got left behind to make it up with the next class. Sounds like it hadn't changed a lot from what Walter has been saying.

Captain

perpet1
January 17th, 2004, 12:19 AM
grazie42,

It's because most people agree with you and would rather take a class with low standards that those classes are the most popular. I believe it will always be that way. In fact, if some agency would start offering the 30 min class I outlined earlier, it would soon surpass PADI as the largest certification agency in the world. Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.


Now I am not a PADI advocate but this is uncalled for Walter. Both PADI and YMCA use the same source to derive their standards (world recreational scuba training counsel). I am willing to bet the standards between the two are almost the same for open water. I am also betting you are going beyond what is actually written in the YMCA standard to teach your classes.

I am not saying this is bad but if there were a YMCA instructor not teaching PPO2 I am betting they would not be in violation of the YMCA standard.

Yes I did say PADI and YMCA BOTH derive their standards from the same place so you are out to lunch stating that one is that much beter then the other.

YES, I will site my source: http://www.wrstc.com/agency.php?country=usa

For thos that don't know the WRSTC is a group that many of the agencies use to develop a set of consistant standards for teaching SCUBA. Both PADI and YMCA are members so for a YMCA instructor to put down PADI is almost funny. Please do not take my word for it. Here is a link the the open water scuba standard http://www.wrstc.com/downloads/Open%20Water%20Certification.pdf





Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.

It is laugh out loud funny that your attitude that you are that much better since most agencies teach by the same standard INCLUDING YMCA.


PLEASE Walter proove me wrong. Quote the YMCA standard where it says you have to present daltons pressure law. I am an instructor as well and although I do teach PPO2 I know it is technically above what I need to teach.

Wendigo
January 17th, 2004, 05:00 AM
Perpet1, I have a lesson plan sitting before me right now. I and Walter are not going "beyond what is actually written in the YMCA standard to teach your classes." It is the criteria, period. If you don't believe me, come on down and I will read it to straight out of our manual.

I know that 90% of you all know that we as YMCA instructors teach our student significantly more than the industry thinks is necessary. It's alomst looked upon as a stigma that we "over-educate" our divers. Many of you look down upon us for that very fact. Well, I for one take pride in the fact that some of my OW student are more advanced than many of you were till you took AOW or nitrox classes.

And we will continue to teach exactly what we have been teaching until I am too decrepit to do so.

Yes, you would be in violation of YMCA SCUBA OW certification criterion if you were to exclude teaching PPO2.


Yes I did say PADI and YMCA BOTH derive their standards from the same place so you are out to lunch stating that one is that much beter then the other.
That obviously just isnt at all true. I challenge anyone to bring a 3-day PADI or SSI OW student against even the weakest of my YMCA SCUBA OW students. I double dare you.

We create some of the safest and most knowledgable new divers in the world. NAUI is the only other agency that is comparable, in my opinion.

you can flame me as you like now, I kind of expect it :lol3:

MikeFerrara
January 17th, 2004, 08:51 AM
Jumping ahead from the argument of what needs to be included in an OW class to enable some one to survive a 60 ft dive...

There many reasons that I want my students to understand simple gas laws. Look how so many new divers dive. They get certified in 30 ft of water and promptly take a trip to Cozumel where they're going to do between 3 and 5 dives a day with some being to depths of 100+ feet. There's also a good chance they'll just follow and rely on a DM for their decompression planning. The DM is likely following a computer and maybe barely keeping in the "green" whatever "green is suposed to mean. LOL These divers have as much or more need to understand some basic decompression theory and the advantages of nitrox than any one else in diving.

Any one here know what the average ascent rate is for an OW diver ascending from their safety stop to the syrface?

Classes may arguably prepare a new diver to survive a shallow dive where there isn't anything to damage but those aren't the kinds of dives they're going to do.

IMO, at least part of the reason these divers aren't very good in the water (the other is just a lack or practice in training) is because they don't understand the mechanics of it or the implications. This sets them up to just go out and gain experience practicing doing things poorly which gets them no place at all.

dbulmer
January 17th, 2004, 08:58 AM
We create some of the safest and most knowledgable new divers in the world. NAUI is the only other agency that is comparable, in my opinion.


BSAC, CMAS will give you a run for your money too since you mentioned the world - I guess there might be other agencies (is GUE an agency?) too come to think of it. :)

RiverRat
January 17th, 2004, 09:59 AM
Jumping ahead from the argument of what needs to be included in an OW class to enable some one to survive a 60 ft dive...

There many reasons that I want my students to understand simple gas laws. Look how so many new divers dive. They get certified in 30 ft of water and promptly take a trip to Cozumel where they're going to do between 3 and 5 dives a day with some being to depths of 100+ feet. There's also a good chance they'll just follow and rely on a DM for their decompression planning. The DM is likely following a computer and maybe barely keeping in the "green" whatever "green is suposed to mean. LOL These divers have as much or more need to understand some basic decompression theory and the advantages of nitrox than any one else in diving.

Any one here know what the average ascent rate is for an OW diver ascending from their safety stop to the syrface?

Classes may arguably prepare a new diver to survive a shallow dive where there isn't anything to damage but those aren't the kinds of dives they're going to do.

IMO, at least part of the reason these divers aren't very good in the water (the other is just a lack or practice in training) is because they don't understand the mechanics of it or the implications. This sets them up to just go out and gain experience practicing doing things poorly which gets them no place at all.


Hey Mike,
Pretty scary....This is exactly what I just did! Well not exactly, but after my cert dives I booked a trip to Cayman. I did consider shallower diving in the Keys but thought I would have a better chance of good diving in GC weather wise. So I went from 30ffw dives to 100fsw+ dives. I bought a computer and was GLAD I did, especially given the multiprofile dives we were doing. I saw and learned from some fantastic divers out there but I also saw a few scary divers. Like you said, basically following DM's profile but none of their own, VERY fast ascents from 100fsw dives, poor buddy skills etc. Maybe this is why I hear a good majority of accidents occur with new divers with only say 20 - 50 dives or so? And yes, I got the Nitrox cert. BIG plus! Almost everyone on that trip was diving Nitrox by the way.
Anyway, keep doing what you're doing!

perpet1
January 17th, 2004, 11:08 AM
Perpet1, I have a lesson plan sitting before me right now. I and Walter are not going "beyond what is actually written in the YMCA standard to teach your classes." It is the criteria, period. If you don't believe me, come on down and I will read it to straight out of our manual.

I know that 90% of you all know that we as YMCA instructors teach our student significantly more than the industry thinks is necessary. It's alomst looked upon as a stigma that we "over-educate" our divers. Many of you look down upon us for that very fact. Well, I for one take pride in the fact that some of my OW student are more advanced than many of you were till you took AOW or nitrox classes.

And we will continue to teach exactly what we have been teaching until I am too decrepit to do so.

Yes, you would be in violation of YMCA SCUBA OW certification criterion if you were to exclude teaching PPO2.


That obviously just isnt at all true. I challenge anyone to bring a 3-day PADI or SSI OW student against even the weakest of my YMCA SCUBA OW students. I double dare you.

We create some of the safest and most knowledgable new divers in the world. NAUI is the only other agency that is comparable, in my opinion.

you can flame me as you like now, I kind of expect it :lol3:

OK Proove that PPO2 is required per the YMCA STANDARD. In other words what does the YMCA standard say with regards to Daltons pressure law. I am betting that neither PPO2 nor the word Dalton appear anywhere in your standards. Remember I asked what the "standard" says, Lesson Plans ARE NOT STANDARDS! Now dust off that book on your shelf and see what is actually required PER STANDARD.

As an Instructor you can teach beyond the letter of the standard (at least in most agencies YMCA and NAUI being the two that you pointed out). All I am saying is thet the written standard for both are comperable given that they come from the same place.

For a YMCA instructor to put down the written standard for PADI is kind of funny. Now the way instructors apply it can be discussed and that is completly subjective and you will get a lot of arguement BUT if you put the stnadards used next to each other they will be pretty much the same.



Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.

Walter was very pointed that it was the standards that are the base of the arguement. I could reply that sure I will develop my own agency (just kidding but there is a point here someplace) and I will subscribe to the WRSRC and guess what....... my written standard would look just like YMCA, PADI, etc.


I guess I am saying the standards are pretty much the same. Now this says nothing about Instructor quality or how an agency recommends or markets a class. Those things you could argue about (I would not argue because I too have reservations regarding the marketing efforts of some agencies) but do not think for a second the core requirements are that much better.

Wendigo
January 17th, 2004, 02:18 PM
"Due to our high standards, YMCA SCUBA remains the only SCUBA certification organization in the United States to offer the C.M.A.S. international certification card."
-YMCA SCUBA website


There is a reason for that.

perpet1
January 17th, 2004, 03:33 PM
"Due to our high standards, YMCA SCUBA remains the only SCUBA certification organization in the United States to offer the C.M.A.S. international certification card."
-YMCA SCUBA website


There is a reason for that.

And this proves what? Thats right, absolutly nothing. I am not saying that one organization is better then another. You are living in in la-la land if you think the standards for open water certification for PADI and any other organization that uses the WRSTC standards are vastly different. You can fool yourself into thinking your organization is superior (I personally think that YMCA delivers a VERY good open water course compared to others BUT that is due more to execution then core standards) BUT the core requirements are the same.

So does the YMCA Standard mention PPO2 or Daltons? Answer: NO

Is it ok for you to teach it? Answer: Absolutly

Would a YMCA Instructor that does not teach it be in violation of standards? Answer: NO

Walter
January 17th, 2004, 06:48 PM
perpet1 ,

"Both PADI and YMCA use the same source to derive their standards (world recreational scuba training counsel)."

Neither derive their standards from that source. Agencies may modify their standards from time to time based on recommendations from the RSTC, but the agencies are the source for RSTC recommendations, not the other way around. YMCA standards are very close to what they were before the RSTC was formed.

"I am willing to bet the standards between the two are almost the same for open water."

How much are you willing to bet?

"I am also betting you are going beyond what is actually written in the YMCA standard to teach your classes."

Now, that is true.

"I am not saying this is bad but if there were a YMCA instructor not teaching PPO2 I am betting they would not be in violation of the YMCA standard."

I've never said teaching PPO2 was required. Dalton's Law is required, although you are correct that the standards do not list the individual gas laws.

"Yes I did say PADI and YMCA BOTH derive their standards from the same place"

Yes, you did and yes, you were mistaken when you said it.

"so you are out to lunch stating that one is that much beter <sic> then <sic> the other."

First, I don't remember making such a statement in this thread. Second, any such statement would be opinion. Third, even if they did both state with the same source (which they didn't), any changes either of them made from that beginning point could (and probably would) make one set of standards better than the other. Fourth, IMO, YMCA's standards are far better than PADI's. We can go into details as to why I have that opinion, if you'd like.

"YES, I will site my source: http://www.wrstc.com/agency.php?country=usa"

Your "source" merely says which 5 American agencies are members of the RSTC. If you are claiming PADI & YMCA are both members, you've proved a point no one is disputing. If you are claiming they have the same standards or derived their standards from a single source, you've proved nothing.

"For thos <sic> that don't know the WRSTC is a group that many of the agencies use to develop a set of consistant <sic> standards for teaching SCUBA."

Again, you are misinformed. The RSTC sets minimums. Any agency can exceed those minimums. Some do, others don't. They certainly don't "develop a set of consistent standards for teaching SCUBA."

"It is laugh out loud funny that your attitude that you are that much better since most agencies teach by the same standard INCLUDING YMCA."

Have you ever looked at standards from different agencies? I have. I've never seen any two that were the same. If you find two that are the same, I'd love to see them.

"if you put the stnadards <sic> used next to each other they will be pretty much the same."

Before I show you where I've done this, I want to know how much you're willing to bet.

"I guess I am saying the standards are pretty much the same."

I guess you are, that's obvious. It's also obvious you've never looked at standards from different agencies.

dbulmer,

"BSAC, CMAS will give you a run for your money too since you mentioned the world - I guess there might be other agencies (is GUE an agency?) too come to think of it. :)"

BSAC and CMAS are both agencies with very high standards. GUE doesn't teach OW divers yet, although when they do, I would expect their standards to be top notch. I would also include LA County as arguably the best in the world.

diverbrian
January 17th, 2004, 07:38 PM
In the classes that I assist with, we teach PP of Nitrogen and Oxygen and do the equations on the whiteboard that show how you get to 1.4 PO2's. Of course, we teach a nitrox cert with our open water so that our OW students come out of the course with a nitrox cert.

You should have seen us trying to explain to an engineer why Table 3 (Residual Nitrogen) tables work that the way that they do. It took some doing to explain that although those tables have minutes at depth listed, that it isn't an exact science.

BTW, Dalton's Law comes in REAL handy when when talking about nitrogen narcosis. And many OW students from here do go to places like the Caribbean where a DM will take them to 100 ft. or better, so yes, we do feel that it is important to talk about narcosis. This is where Mike F. has a valid point. Dive tables are conveinent to explain residual nitrogen as well. We also show dive profiles from our dive computers to show the students what a "real world" dive looks like.

diverbrian
January 17th, 2004, 07:41 PM
That is the law that explains pressure/temperature relationships.

That was Charles Law. Oops!

perpet1
January 17th, 2004, 08:13 PM
perpet1 ,

"I guess I am saying the standards are pretty much the same."

I guess you are, that's obvious. It's also obvious you've never looked at standards from different agencies.



There my friend you are very wrong as I am multi agency certified and I do read what the standards actually say not just read them for what I believe they should say. Although I have to admit YMCA is not one of them. You did admit that you are reading into the standards to figure out what gas laws you need to teach since as you say it is not specified.

perpet1
January 17th, 2004, 08:22 PM
There my friend you are very wrong as I am multi agency certified and I do read what the standards actually say not just read them for what I believe they should say. Although I have to admit YMCA is not one of them. You did admit that you are reading into the standards to figure out what gas laws you need to teach since as you say it is not specified.


Walter, you also did not answer the question that goes to the heart of this thread,

If a YMCA instructor were to not teach PPO2 would they be in violation of the YMCA standard?

perpet1
January 17th, 2004, 08:43 PM
perpet1 ,

"Both PADI and YMCA use the same source to derive their standards (world recreational scuba training counsel)."

Neither derive their standards from that source. Agencies may modify their standards from time to time based on recommendations from the RSTC, but the agencies are the source for RSTC recommendations, not the other way around. YMCA standards are very close to what they were before the RSTC was formed.

"I am willing to bet the standards between the two are almost the same for open water."

How much are you willing to bet?

"I am also betting you are going beyond what is actually written in the YMCA standard to teach your classes."

Now, that is true.

"I am not saying this is bad but if there were a YMCA instructor not teaching PPO2 I am betting they would not be in violation of the YMCA standard."

I've never said teaching PPO2 was required. Dalton's Law is required, although you are correct that the standards do not list the individual gas laws.

"Yes I did say PADI and YMCA BOTH derive their standards from the same place"

Yes, you did and yes, you were mistaken when you said it.

"so you are out to lunch stating that one is that much beter <sic> then <sic> the other."

First, I don't remember making such a statement in this thread. Second, any such statement would be opinion. Third, even if they did both state with the same source (which they didn't), any changes either of them made from that beginning point could (and probably would) make one set of standards better than the other. Fourth, IMO, YMCA's standards are far better than PADI's. We can go into details as to why I have that opinion, if you'd like.

"YES, I will site my source: http://www.wrstc.com/agency.php?country=usa"

Your "source" merely says which 5 American agencies are members of the RSTC. If you are claiming PADI & YMCA are both members, you've proved a point no one is disputing. If you are claiming they have the same standards or derived their standards from a single source, you've proved nothing.

"For thos <sic> that don't know the WRSTC is a group that many of the agencies use to develop a set of consistant <sic> standards for teaching SCUBA."

Again, you are misinformed. The RSTC sets minimums. Any agency can exceed those minimums. Some do, others don't. They certainly don't "develop a set of consistent standards for teaching SCUBA."

"It is laugh out loud funny that your attitude that you are that much better since most agencies teach by the same standard INCLUDING YMCA."

Have you ever looked at standards from different agencies? I have. I've never seen any two that were the same. If you find two that are the same, I'd love to see them.

"if you put the stnadards <sic> used next to each other they will be pretty much the same."

Before I show you where I've done this, I want to know how much you're willing to bet.

"I guess I am saying the standards are pretty much the same."

I guess you are, that's obvious. It's also obvious you've never looked at standards from different agencies.

dbulmer,

"BSAC, CMAS will give you a run for your money too since you mentioned the world - I guess there might be other agencies (is GUE an agency?) too come to think of it. :)"

BSAC and CMAS are both agencies with very high standards. GUE doesn't teach OW divers yet, although when they do, I would expect their standards to be top notch. I would also include LA County as arguably the best in the world.

Interesting article http://www.iit.edu/~elkimar/design/organizations/

Walter
January 17th, 2004, 09:38 PM
diverbrian,

"I thought...That was Charles Law."

Most people do, but Charles' Law deals with temperature/volume relationships. Important law for hot air ballooning, but no SCUBA applications.

perpet1,

"Walter, you also did not answer the question that goes to the heart of this thread,

If a YMCA instructor were to not teach PPO2 would they be in violation of the YMCA standard?"

I believe I did answer that.

"I've never said teaching PPO2 was required."

It is an interesting article. It's full of errors, but I agree it's interesting.

jonnythan
January 17th, 2004, 10:00 PM
diverbrian,

"I thought...That was Charles Law."

Most people do, but Charles' Law deals with temperature/volume relationships. Important law for hot air ballooning, but no SCUBA applications.


You know, all of those "laws" are really just different parts of the same simple equation..

P1 x V1 / T1 = P2 x V2 / T2

diverbrian
January 17th, 2004, 10:11 PM
You know, all of those "laws" are really just different parts of the same simple equation..

P1 x V1 / T1 = P2 x V2 / T2

I believe that I was taught that one in high school physics and nuclear power school a few years later. Both places called it the "Universal Gas Law."

Don Burke
January 17th, 2004, 10:16 PM
You know, all of those "laws" are really just different parts of the same simple equation..

P1 x V1 / T1 = P2 x V2 / T2

It will be interesting to see you pull Henry's Law out of that equation.

jonnythan
January 17th, 2004, 10:22 PM
It will be interesting to see you pull Henry's Law out of that equation.

Henry's Law isn't exactly BOW material.

Besides, I meant Boyle's and Charles' laws. And you know it :P

perpet1
January 17th, 2004, 10:30 PM
perpet1,

"Walter, you also did not answer the question that goes to the heart of this thread,

If a YMCA instructor were to not teach PPO2 would they be in violation of the YMCA standard?"

I believe I did answer that.

"I've never said teaching PPO2 was required."

It is an interesting article. It's full of errors, but I agree it's interesting.



"Required per standard or is it just something you present?"

Required per standard. How do you explain the theory of decompression without discussing Dalton's Law of partial pressures?

Sure you already answered the question...... You covered your bases just fine, it is required not then again it is not required.

Then you make the comment like the following:



Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.


so it is easy to site that an artical is full of errors and back it up with your years of experience and >4000 posts but it means little.

Walter
January 17th, 2004, 11:00 PM
Errors in the article:

"All basic open-water courses must include the same syllabus of diving skills, physics, physiology, etc."

They do not have the same syllabus.

"It was written by the Recreational Scuba Training Council"

It was written by representatives from NASDS, NAUI, PADI, SSI and YMCA before the RSTC was formed. The RSTC was formed later and now the RSTC is the group that makes changes to the minimums.

"Although only six agencies are members of RSTC, as a practical matter all have to meet the RSTC/ANSI standard in order to buy liability insurance and defend themselves from lawsuits."

NAUI is not a member and no longer meets the minimum swimming requirements, yet it has no difficulty with liability insurance.

"Some agencies (IDEA, NASDS and YMCA) require a minimum number of hours of instruction, typically 24............Other agencies require that students meet performance standards, and leave the number of lecture hours and pool sessions up to the instructor."

The agencies I've studied all use performance requirements rather that strict hour requirements.

"NAUI, PDIC and YMCA require four scuba and one skin dive."

I don't know PDIC's requirements. That is correct for YMCA, but NAUI requires either 5 SCUBA or 4 SCUBA and 1 skin dive.

"Of course, individual instructors can exceed an agency's minimum standards, and many do."

This is misleading. Instructors from some agencies (YMCA & NAUI are examples) can require additional material while instructors from other agencies (PADI is an example) can offer, but cannot require additional material.

Yes, it's full of errors. What's left out of the article is even more misleading than the errors included.

Walter
January 17th, 2004, 11:05 PM
jonnythan,

"Henry's Law isn't exactly BOW material."

Why isn't it? It is essential to decompression theory.

"I meant Boyle's and Charles' laws."

Charles' Law has nothing to do with SCUBA.

"You know, all of those "laws" are really just different parts of the same simple equation"

The general gas law is derived from combining various gas laws. OTOH, most students can grasp the concepts easier when they are presented separately.

jonnythan
January 17th, 2004, 11:10 PM
jonnythan,

"Henry's Law isn't exactly BOW material."

Why isn't it? It is essential to decompression theory.


Are you saying OW students actually compute the volume of gas dissolved into their bloodstream? Sounds like something I had to do on one of my Advanced Systems Phisiology finals.

Walter
January 17th, 2004, 11:27 PM
"Are you saying OW students actually compute the volume of gas dissolved into their bloodstream?"

No.

perpet1
January 17th, 2004, 11:37 PM
Errors in the article:

"All basic open-water courses must include the same syllabus of diving skills, physics, physiology, etc."

They do not have the same syllabus.

Your right but the members have the same minimum standard so we can start splitting hairs.

"It was written by the Recreational Scuba Training Council"

It was written by representatives from NASDS, NAUI, PADI, SSI and YMCA before the RSTC was formed. The RSTC was formed later and now the RSTC is the group that makes changes to the minimums. OK and you are saying what exactly? This is relavant how? you are arguing the chicken or the egg but it does not really matter.

"Although only six agencies are members of RSTC, as a practical matter all have to meet the RSTC/ANSI standard in order to buy liability insurance and defend themselves from lawsuits."

NAUI is not a member and no longer meets the minimum swimming requirements, yet it has no difficulty with liability insurance. Your 100% correct

"Some agencies (IDEA, NASDS and YMCA) require a minimum number of hours of instruction, typically 24............Other agencies require that students meet performance standards, and leave the number of lecture hours and pool sessions up to the instructor."

The agencies I've studied all use performance requirements rather that strict hour requirements. and that make this statement incorrect how?

"NAUI, PDIC and YMCA require four scuba and one skin dive."
I don't know PDIC's requirements. That is correct for YMCA, but NAUI requires either 5 SCUBA or 4 SCUBA and 1 skin dive. OK we have already established NAUI is not a member of RSTC Besides how is referencing NAUI incorrect here, we establishe they can all go beyond the requirements and in practice most NAUI instructors opt for the 4+1 format. But you did proove you vast understanding of the standards.

"Of course, individual instructors can exceed an agency's minimum standards, and many do."

This is misleading. Instructors from some agencies (YMCA & NAUI are examples) can require additional material while instructors from other agencies (PADI is an example) can offer, but cannot require additional material. I agree totally but in context there was nothing wrong with the statement.

Yes, it's full of errors. What's left out of the article is even more misleading than the errors included.

Yes full of errors. But generally speaking the author was correct that most open water classes have the same humble beginings.

BTW one would have a hard time finding ANY article (or standard for that matter) that could not be picked apart if one were to look hard enough.

perpet1
January 17th, 2004, 11:43 PM
The general gas law is derived from combining various gas laws. OTOH, most students can grasp the concepts easier when they are presented separately.

I could not agree more.

Don Burke
January 17th, 2004, 11:46 PM
Henry's Law isn't exactly BOW material.

Besides, I meant Boyle's and Charles' laws. And you know it :P

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
January 18th, 2004, 01:59 PM
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.

diverbrian
January 18th, 2004, 02:35 PM
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 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.

Walter
January 18th, 2004, 05:11 PM
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.

grazie42
January 19th, 2004, 05:39 AM
Walter once bubbled...

It's because most people agree with you and would rather take a class with low standards that those classes are the most popular. I believe it will always be that way. In fact, if some agency would start offering the 30 min class I outlined earlier, it would soon surpass PADI as the largest certification agency in the world. Since you believe so strongly about leaving out nonessentials from an OW course, perhaps you should start an agency with such standards.

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...

Walter
January 19th, 2004, 08:06 AM
"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.

grazie42
January 19th, 2004, 08:42 AM
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...

Walter
January 19th, 2004, 11:03 AM
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.

truva
January 19th, 2004, 03:47 PM
...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 doesn’t then it is only in it for the money and it doesn’t have its students best interests in mind.

Truva

grazie42
January 20th, 2004, 04:03 AM
Walter,
"I believe it is important to understand the concepts of partial pressure to understand decompression concepts and oxygen toxicity".
Ok, lets agree to disagree then...I don´t think pp is important in understanding decompression concepts (and I do not believe oxygen toxicity should be taught in OW). As for not calculating pp02 while teaching about it, it was entirely my assumtion that teaching about pp02 also included calculating it (propably because calculating helped my understanding of it). The more we discuss this the part of instruction about pp02 in your class seems to be shrinking...maybe this is because I associate pp02 with Nitrox classes were pp02 is a big part and because you seemed to "make a big deal" about including it in your teaching or maybe I misunderstood you...either way I feel that the gap between our views seems to be shrinking, do you?
I am not going to argue about whether what I said differ from what I meant to say or not (as a more unproductive argument is hard to find).

Truva,
I don´t understand the point of the first part of your post..."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 couldn´t agree more...

"I am suspect of any program that does not recognize how it is being used and adjust of it. If it doesn’t then it is only in it for the money and it doesn’t have its students best interests in mind."
To my mind, criticizing any system, from the point of view of those who don´t play by it´s rules is like saying that laws are bad because people brake them...Maybe speedlimits should be raised because people are obviously driving too fast...somehow this argument doesen´t stick and neither does the one (if that is your intention) about divers violating the depth rules of their certification.

Maybe you´d care to elaborate?

truva
January 20th, 2004, 01:59 PM
Truva,
I don´t understand the point of the first part of your post..."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 couldn´t agree more...

Maybe you´d care to elaborate?

Well, following this thread I have found it very enlightening or interesting rather that some agencies (seems PADI is one) want their OW certification holders to have a depth limit 60 feet. Why set a “limit” like this that no one seems to follow and a limit that is pretty stupid when you think about it.

Anyway this thread got off into the merits of teaching or rather exposing students to more complete information, kind of letting people know what they don’t know and is this a good idea or not. My opinion is that all information is good and what you are really doing in the OW class is giving people a start to learn how to do this safely. What makes a safe diver is diving and information, but then the diver has to care.

Personally I see no reason for the AOW certification, nothing here you cannot learn by doing and maybe some reading. Same deal with Nitrox, I really cannot see what you need to know about this that you cannot find readily available.

Truva

Groundhog246
January 20th, 2004, 06:23 PM
..some agencies (seems PADI is one) want their OW certification holders to have a depth limit 60 feet. Why set a “limit” like this that no one seems to follow and a limit that is pretty stupid when you think about it.

Personally I see no reason for the AOW certification, nothing here you cannot learn by doing and maybe some reading. Same deal with Nitrox, I really cannot see what you need to know about this that you cannot find readily available.

Truva

Why have OW training then? Buy the manual, read it, go diving. The OW limit and ONE of the reasons for AOW is "nitrogen narcosis". It's generally accepted that you need to be well under 60 feet to get narcd. Also the average newer diver, with an AL80 or smaller is unlikely to have enough air to exceed the NDL's on a single dive to less than 60 feet. Many would have trouble getting tanks swapped and back in the water fast enough to do 2 repetitive dives to 60 feet and accumulate enough bottom time to exceed the NDL's. At the 90 to 100 feet, it's a lot easier to incur that deco obligation.
he LDS where we trained (NAUI) recommends 15 to 20 dives after your OW to get your buoyancy settled down and your comfort level up, before doing AOW (may be thier recommendation, not NAUI). Then you learn to handle other tasks, such as navigation, searches, night diving and the extra task loading that goes with them. They take you on a well escorted deep dive and ask you to perform some relativley simple skills at depth to demonstrate the effects of narcosis. It's kinda like taping someone who's impaired and showing them later how impaired they were, only no taping. I don't think the same dive, without the guidance of someone much more experienced, would have near the same value.
As far as Nitrox. I've seen way to many who struggle with dive tables, which to me are way simple, to think they'd ever learn to compute PPO2 limits on their own. Much less analyzing O2 levels, etc.

truva
January 20th, 2004, 06:59 PM
Why have OW training then? Buy the manual, read it, go diving.

But I would add that while it would be easier do get instruction in a class, you can get plenty of pointers from other divers to help you along the way. I know when I started I got a lot help from others and have returned the favor when I have been approached.

Anyway, IMHO I liked what the YMAC program gave me years ago as opposed to a 60-foot depth limit. You need to cover/know this stuff because expecting an OW diver to adhere to this is unrealistic. The YMAC did cover partial pressures and nitrogen narcosis, I am not trying to say that they covered this in depth but they do give you what you need to know to go find out.

Knowing what that you do not know is potentially very important information to have.

Truva

paolov
January 29th, 2004, 01:00 AM
this entire thread started from PPO2, started by 911.

Then it went to agency bashing and memeber bashing by way of who is right or wrong.

the thread is on the question of 911 on PPO2, which has been answered already by alot of correct answers.

911 is asking then for a dive profile he would like to make. I think he should take the necessary knowledge before doing his dives.

Since 911 question has been answered, its his problem in choosing which advise he would take.

Lets stop this bashing around and proving who is right or wrong.

I think we would all agree for 911 to make his studies in a proper conducive learning environment. it's his life and his buddies that's in line. We have contributed to his question .

:icosm10:

grazie42
January 29th, 2004, 04:47 AM
Paolov, about the changes in the thread...I think it´s called evolution :-)
Truva: I agree with you, I don´t see much reason for the 60ft depth limit but if I train with PADI (or anyone else) I make a commitment to follow their rules and regulations (at least for the duration of the class). That people (including me) don´t always follow these rules when on their own is really their problem, not PADI´s, who expect people to follow their rules (realistic or not).

For me AOW was about getting a hang of Nav & Search and Recovery and getting the certification that I need to go on live-aboards (and other fun trips). I think the AOW was good value-for-money, feel free to disagree.

I´m not saying you can´t learn the things they teach in AOW on your own just as its possible to learn how to read without instruction but why re-invent the wheel? Only reason for this (as I see it) would be if you had plenty of time and limited resources (=money) but that doesen´t change the fact that instruction is more efficient. I too have learned a lot from other divers in various situations (SB for example) but I don´t doubt that I´d have learnt a lot more in shorter time if I´d had a good instructor to dive with and ask questions after/during every dive than I have...

As for pp02 I still don´t see the point of it in OW. (let´s agree to disagree)

Walter
January 29th, 2004, 12:19 PM
paolov ,

The thread was effectively dead 9 days ago. Thanks for starting it back up.


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