Can some explain to me what PPO2 is?

[Diver0001]

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]

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]

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]

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]

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]

Walter,
what is Amonton? You've got me stumped there.

 

[Walter]

That is the law that explains pressure/temperature relationships.

 

[cornfed]

That is the law that explains pressure/temperature relationships.

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/gaslaws3.html#amonton

 

[Wendy]

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]

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/gaslaws3.html#amonton

Cornfed,Walter

Thank you - off to do some reading.