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brojack17
01-06-2010, 21:25
For you Nitrox divers out there with your own tanks. Do you dive Nitrox exclusively? How often do you dive with regular air?

navyhmc
01-06-2010, 22:18
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.

Vercingetorix
01-06-2010, 22:25
Remember though, Nitrox will be most beneficial if you are hitting your NDL. If you're running out of air before NDL, it will not help to extend your bottom time.

That said, some will argue that it makes them feel better after a dive or that it will reduce possibility of DCS. So, there is some benefit there.

FishFood
01-06-2010, 22:32
90% of the time I just dive air. The depths and bottom times around here don't warrant the extra cost of the nitrox. Ill usually dive it out in the gulf where the dives are deeper and repetitive but that's about it. Everyone around here banks 32% so it's there when I need it w/o having to have o2 clean tanks.

jugglematt
01-06-2010, 23:07
for me its almost every dive on nitrox

mix my own fills and pump my own tanks , so after the setup the cost price is reasonable.

i try to dive on high o2 mixes (36-40%) at the moment for added safety and use air tables or set my computer to maximum conservative level.
from what i understand for a diver who is getting older or who is unfit or who is carrying extra weight or has a history of DCS diving nitrox is very beneficial .

i definitely feel better after a nitrox dive , particularly with depths around 30m . less fatigue and clearer whilst on the dive .

Matty

mitsuguy
01-06-2010, 23:39
the only time I dive Nitrox is when I am on dive 4 and 5 on the same day and they were all to 70 feet or more... anything less is just a waste to me - almost all of our dives are spent with the first half around 70 feet, second half around 30 feet...

every once in a while, when going on fun dives to the wrecks or other dives without a second level, we'll do nitrox just to shorten our surface intervals, for the most part... the group I dive with is all really good on air, I would say we are all in the .4 range, which given a 500 psi buffer, even on an AL80, we can all spend around 40 minutes at 100 feet, and the NDL for 100 feet is 20 minutes... Nitrox can definitely be a help there :)

Diver Kat
01-07-2010, 00:03
When traveling, we pretty much always use Nitrox on the first dive and air on the 2nd. We just like the additional safety factor and it doesn't hurt with the SI's either. Our trips to Bonaire we did Nitrox exclusively due to the number of consecutive dives and dive days. And we did seem to feel less tired ...

CompuDude
01-07-2010, 02:03
I try to use Nitrox on all boat dives, or at least for the first one if the boat can't provide Nitrox. Occasionally I'll bring two tanks, if it's warranted, and just dive an air refill for the third. (SoCal boats almost all have compressors)

Shore dives I tend towards air, although there are a few sites where Nitrox is warranted, and then I'll dive Nitrox.

Banked or Membrane-supplied Nitrox is readily available to me, so I don't maintain any o2-clean tanks, and I can switch back and forth at will.

chinacat46
01-07-2010, 05:22
Out of 1011 dives I've done 753 on nitrox. Mostly 32% but a few were 36% and few(on the Nekton) were about 28%.

wxboy911
01-07-2010, 07:22
Last season I would say just over half were 32%...I grabbed a quick air fill for dives that were spur of the moment. If my lds had Nitrox I would dive it for every dive...as it is now I have to drive 45 min for a Nitrox fill.

ScubaToys Larry
01-07-2010, 07:26
Yes!

As for frequency, it's usually about 75% Nitrox vs. 35% air.

So how's the math part of the DM studying going?? :smiley36:

Good to see you're one of those guys that gives 110%!

skdvr
01-07-2010, 07:52
I would say I do about 60% air and 40% Nitrox. Most of the time is was because I did not fell like messing with leaving my tanks at the shop over night for a PP fill. This year I am mixing my own so I will probably be diving it more.

Phil

skdvr
01-07-2010, 07:54
Yes!

As for frequency, it's usually about 75% Nitrox vs. 35% air.

So how's the math part of the DM studying going?? :smiley36:

Good to see you're one of those guys that gives 110%!

Remember though Larry, those Navy guys never could do math

Phil

navyhmc
01-07-2010, 08:03
Yes!

As for frequency, it's usually about 75% Nitrox vs. 35% air.

So how's the math part of the DM studying going?? :smiley36:

Good to see you're one of those guys that gives 110%!

Remember though Larry, those Navy guys never could do math

Phil

It has it's advantages: Navy Beer Math: 2 cans per person and a team of 7 = 5 cases!!! :smiley36:

note to self: Never do math after doing Beer Math! :smilie39:

theduckguru
01-07-2010, 11:50
Yes!

As for frequency, it's usually about 75% Nitrox vs. 35% air.

So how's the math part of the DM studying going?? :smiley36:

Good to see you're one of those guys that gives 110%!

Seven out of 5 people have trouble with fractions.

UCFKnightDiver
01-10-2010, 09:54
Almost exclusively dive nitrox 32%

Splitlip
01-10-2010, 10:04
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.


110%???Hmmm

FishFood
01-10-2010, 12:11
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.


110%???Hmmm

Day late and a dollar short Bub.

RogerAg
01-10-2010, 13:14
When traveling, we pretty much always use Nitrox on the first dive and air on the 2nd. We just like the additional safety factor and it doesn't hurt with the SI's either. Our trips to Bonaire we did Nitrox exclusively due to the number of consecutive dives and dive days. And we did seem to feel less tired ...

In Hawaii I usually use Air on my first dive and NITROX on my second dive.
When I shore dive I can plan the dive the day before and even though I use dive computers now, I still try to do the deepest dive first (old habits are hard to brake.)

If I dive from a boat, the crew usually have us do the deepest dive first so again Air first, NITROX second.
NITROX is expansive in Hawaii so I don't do for every dive.

My 13 cu. ft. Pony always has NITROX in it, I fill it myself from my wife's tank before her dive. I like to suck on it at my 15 foot safety stop. At 20 feet I can suck on that tank for 12 minutes.

Aquatrax
01-10-2010, 13:28
Does a 21% mix count?

ssmdive
01-10-2010, 13:34
Recreational dives I just use Air. Tech stuff is Nitrox.

in_cavediver
01-10-2010, 15:09
It depends for me - I get air free at home so most localish dives are air. When in N. FL - its almost exclusively nitrox. When up on the great lakes - its a mix but mostly air due to availability.

navyhmc
01-10-2010, 20:10
When you get down to it, it's all voodoo gas and if we breathe more then 21%, we're going to die! :smiley36:

Scuba Pete
01-11-2010, 08:40
I breath Normoxic Nitrox almost exclusivly, except cave diving i use premix 32%.

mitsuguy
01-11-2010, 16:23
I breath Normoxic Nitrox almost exclusivly, except cave diving i use premix 32%.

translation: you use air most the time...

PACKRMAN
01-11-2010, 18:26
When you get down to it, it's all voodoo gas and if we breathe more then 21%, we're going to die! :smiley36:


:smilie39::smilie39:
As opposed to breathing air and we live forever

:smilie39::smilie39:

navyhmc
01-11-2010, 18:33
When you get down to it, it's all voodoo gas and if we breathe more then 21%, we're going to die! :smiley36:


:smilie39::smilie39:
As opposed to breathing air and we live forever

:smilie39::smilie39:

Well....No, you're still going to die....:smilie39: :smilie39:

Splitlip
01-11-2010, 19:15
I dive nitrox exclusively for all intents and purposes.

Multiple "deep" dives from boats, if you are not diving eanx, you either end up cutting dives short, sitting them out on the boat or diving in a chamber.

If diving a local charter, all the more reason to dive nitrox as the have to keep a schedule.

RogerAg
01-12-2010, 12:58
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.

wheelman
01-12-2010, 13:42
Does a 21% mix count?

100% is DEAD.

0% is also 100% dead, not sure what you meant? ox tox?

Aquatrax
01-12-2010, 13:59
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.


Incorrect - Air is a mix of Nitrogen and Oxygen, ergo Nitrox
Correct - Good Answer
Incorrect - 100% O2 has a MOD of 13fsw assuming a PP02 of 1.4

Smashee
01-12-2010, 14:19
100% O2 has a MOD of 13fsw assuming a PP02 of 1.4

It's also been used for deco at a 5m stop. Some divers I've met push the ppO2 envelope and run up to 1.55 during a final stop.
80% is more common and safer. No-one in our club uses 100% for diving.

Oh, I dive almost exclusively Nitrox with mixes ranging from 27% to 36% depending on the site.
If I'm doing a short, shallow shore dive I'll sometimes get the shop to top off with air to save a couple of bucks so I'll end up doing a 10m dive on 24%. :smiley36:

ssmdive
01-12-2010, 14:33
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.


Funny, I don't feel dead and I use 100% O2 quite a bit underwater.

in_cavediver
01-12-2010, 18:55
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.


Funny, I don't feel dead and I use 100% O2 quite a bit underwater.

Me neither. 100% (o2) is very common for me - moreso than 50/50. Something about its a transfill from a storage bottle. Got a couple of steel 45's with 2800 psi of O2 in them now.

I use it at 20ft. PPO2 is around 1.61 or so for deco. Does a great job IMHO.

navyhmc
01-12-2010, 20:31
100% O2 for long periods of time = lung issues. 100% for deco = good times = less time. 100% deeper than 20' for longer than 20 minutes = LD50 for frogmen.

CompuDude
01-12-2010, 22:41
When traveling, we pretty much always use Nitrox on the first dive and air on the 2nd. We just like the additional safety factor and it doesn't hurt with the SI's either. Our trips to Bonaire we did Nitrox exclusively due to the number of consecutive dives and dive days. And we did seem to feel less tired ...

In Hawaii I usually use Air on my first dive and NITROX on my second dive.
When I shore dive I can plan the dive the day before and even though I use dive computers now, I still try to do the deepest dive first (old habits are hard to brake.)

If I dive from a boat, the crew usually have us do the deepest dive first so again Air first, NITROX second.
NITROX is expansive in Hawaii so I don't do for every dive.

My 13 cu. ft. Pony always has NITROX in it, I fill it myself from my wife's tank before her dive. I like to suck on it at my 15 foot safety stop. At 20 feet I can suck on that tank for 12 minutes.

Just curious: Have you actually run the profiles through your computer's simulator to see if it makes a difference to your bottom times to use the Nitrox second as opposed to first?

On boats that don't pump Nitrox, it's quite common to being a tank with Nitrox for the first dive, and then finish up the day on air when they pump air to refill the tank. (or a lower percentage Nitrox if the first dive left a lot of gas for some reason).

LiteHedded
01-13-2010, 08:20
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.
you're silly.

UCFKnightDiver
01-13-2010, 08:23
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.

Huh?

RogerAg
01-13-2010, 10:30
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.


Incorrect - Air is a mix of Nitrogen and Oxygen, ergo Nitrox
Correct - Good Answer
Incorrect - 100% O2 has a MOD of 13fsw assuming a PP02 of 1.4

Sorry but;
Atmospheric Air at sea level is approx. 21% Oxygen, 79% Nitrogen and trace elements. In Scuba diving is always called Air not NITROX.

When you add more Oxygen to the mix it is then called NITROX. See Wikipedia encclopedia

Nitrox
From Wikipedia, the free encyclopedia


Typical Nitrox cylinder marking
Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen, 21% oxygen, and 1% other gases, primarily argon.[1][2][3] However, in scuba diving, nitrox is normally differentiated and handled differently from air.[3] The most common use of nitrox mixtures containing higher than normal levels of oxygen is in scuba, where the reduced percentage of nitrogen is advantageous in reducing nitrogen uptake in the body's tissues and so extending the possible dive time, and/or reducing the risk of decompression sickness (also known as the bends).


Some of the posts say that they use 100% O2?
I don't think that would be called NITROX because you did not mix the gas, Breathing 100% Oxygen underwater is way beyond my training. It would be my understanding that you have to have special regs. and hoses and have your insurance paid up.
What is the safe depth for breathing 100% Oxygen? and were do you fill your tank?

in_cavediver
01-13-2010, 10:48
Does a 21% mix count?

21% is AIR,
22% is NITROX,
100% is DEAD.


Incorrect - Air is a mix of Nitrogen and Oxygen, ergo Nitrox
Correct - Good Answer
Incorrect - 100% O2 has a MOD of 13fsw assuming a PP02 of 1.4

Sorry but;
Atmospheric Air at sea level is approx. 21% Oxygen, 79% Nitrogen and trace elements. That is always called Air not NITROX.

When you add more Oxygen to the mix it is then called NITROX.

Some of the posts say that they use 100% O2?
I don't think that would be called NITROX because you did not mix the gas, Breathing 100% Oxygen underwater is way beyond my training. It would be my understanding that you have to have special regs. and hoses and have your insurance paid up.
What is the safe depth for breathing 100% Oxygen? and were do you fill your tank?

Technically nitrox is a mixture of O2 and N2. It comes in hypoxic, normoxic and hyperoxic flavors. (hypoxic mixes usually come from CCR's most commonly when diving air diluent deep - most other hypoxic mixes have helium as well making it a trimix)

I do use 100% o2 which technically isn't nitrox but a great gas for deco. In this context, it is used at a PO2 of 1.6 at a depth of 20'. It also doubles as emergency o2. Its use is covered in a good deco procedures class or other entry level tec class. O2 is also used for the simpliest rebreathers - o2 rebreathers. This is basically only o2 in the loop with no diluent gas. Good to 20-30' max. (personally - I would lean toward the 10-15ft range and require the FFM in case of oxtox)

Usage of any high 02 nitrox requires 02 clean tanks and 1st stages/SPG. The 2nd stages are not cleaned. This is carried as a second gas for deco so it has only the first stage, 2nd stage and SPG generally. Some CCR divers will add an inflator hose as well.

As for safety - I contend decoing on O2 is safer than deco on backgas. I flush more inert gas quicker - thus limiting hypothermia and time in the water. I can always do surface deco as well. There is a lot of information out there regarding this for those inclined to look. (I can't do the content justice so I won't try - I also don't want to start the debates over 50/50, 80/20 vs 100)

Lastly - availability. I can get O2 to transfill from my local gas supplier or from a nitrox fill station. Some more tec oriented or large nitrox fill stations have Haskels (02 booster pump) to give higher pressure O2 fills. I can get 1500-1700psi transfilling off of a standard 2400psi storage bottle. From a fill station with a booster, I can get 3000psi o2. (or more)

ssmdive
01-13-2010, 13:30
Some of the posts say that they use 100% O2?
I don't think that would be called NITROX because you did not mix the gas, Breathing 100% Oxygen underwater is way beyond my training.
Since it is beyond your training.... Then what gives you the experience to claim: "100% is DEAD."?!?!?!?!?!?!?


It would be my understanding that you have to have special regs. and hoses and have your insurance paid up. :smilie39::smilie39::smilie39:

Again, you glean this expert opinion from?!?!?!? Does it have higher risks? Sure, but so does regular Nitrox.


What is the safe depth for breathing 100% Oxygen?20 feet for a PPO2 of 1.6.


and were do you fill your tank?Almost any tech dive shop or at some peoples garages (We are getting tanks for O2, H, and Argon). For ocean diving many people prefer 80%.

UCFKnightDiver
01-13-2010, 17:17
Heck you can get pure o2 from almost any dive shop as they are most likely doing partial pressure filling with 100% o2 anyways

Aquatrax
01-13-2010, 20:26
It would be my understanding that you have to have special regs. and hoses and have your insurance paid up. :smilie39::smilie39::smilie39:

Again, you glean this expert opinion from?!?!?!? Does it have higher risks? Sure, but so does regular Nitrox.



Apparently, gleaned from the all knowing oracle Wikipedia :smilie39:

RogerAg
01-14-2010, 14:20
It would be my understanding that you have to have special regs. and hoses and have your insurance paid up. :smilie39::smilie39::smilie39:

Again, you glean this expert opinion from?!?!?!? Does it have higher risks? Sure, but so does regular Nitrox.



Apparently, gleaned from the all knowing oracle Wikipedia :smilie39:

First of all this thread was started by brojack17 who only has 21 dives so a lot of what I posted was for his behalf.
Most of my information came from my training manual: "NITROX DIVING, a manual for Recreational Nitrox Scuba Divers, By Fred Calhoun PE, PDIC International.

Another reason not to post that you are using 100% o2 is we also have people reading this posts such as bigman241 who has not even had a regulator in his mouth, he has suggested just breathing from a garden hose, and now he may get the idea that he might just take a o2 tank from his local welding supply shop under water.

I went to the Wikipedia page because someone had stated that "All AIR is NITROX" The Wikipedia page confirmed that he was correct, all AIR is NITROX! But this is a Diving forum so we should use Diving terms. In diving NITROX us a blending of o2 and AIR.
I've been on dives, and I'm sure that you have also where someone makes a statement that their tank is Oxygen, my wife sometimes refers to it as OXYGEN, their statement was somewhat correct it is 20% Oxygen, But in Diving we call it AIR, and we don't call a tank of AIR NITROX.

I made a statement about special regs for 100% o2. My training manual states that o2 content greater than 40% must be cleaned or Oxygen service. It also states; "that some (cylinders, valves and regulators) are not Oxygen compatible".
In my Training Manual it does not go higher then 40%
So in my humble opinion NITROX 22% to 40% is Recreationa and 41% to 100% is teck.

navyhmc
01-14-2010, 18:58
My only caveat to your post Roger is some agencies teach rec nitrox to 50%, other than that, spot on!

Cheers!

in_cavediver
01-14-2010, 19:20
It would be my understanding that you have to have special regs. and hoses and have your insurance paid up. :smilie39::smilie39::smilie39:

Again, you glean this expert opinion from?!?!?!? Does it have higher risks? Sure, but so does regular Nitrox.



Apparently, gleaned from the all knowing oracle Wikipedia :smilie39:

First of all this thread was started by brojack17 who only has 21 dives so a lot of what I posted was for his behalf.
Most of my information came from my training manual: "NITROX DIVING, a manual for Recreational Nitrox Scuba Divers, By Fred Calhoun PE, PDIC International.

Another reason not to post that you are using 100% o2 is we also have people reading this posts such as bigman241 who has not even had a regulator in his mouth, he has suggested just breathing from a garden hose, and now he may get the idea that he might just take a o2 tank from his local welding supply shop under water.

I went to the Wikipedia page because someone had stated that "All AIR is NITROX" The Wikipedia page confirmed that he was correct, all AIR is NITROX! But this is a Diving forum so we should use Diving terms. In diving NITROX us a blending of o2 and AIR.
I've been on dives, and I'm sure that you have also where someone makes a statement that their tank is Oxygen, my wife sometimes refers to it as OXYGEN, their statement was somewhat correct it is 20% Oxygen, But in Diving we call it AIR, and we don't call a tank of AIR NITROX.

I made a statement about special regs for 100% o2. My training manual states that o2 content greater than 40% must be cleaned or Oxygen service. It also states; "that some (cylinders, valves and regulators) are not Oxygen compatible".
In my Training Manual it does not go higher then 40%
So in my humble opinion NITROX 22% to 40% is Recreationa and 41% to 100% is teck.

The only caveat is that this is a forum for all divers. I have a PADI book from the late 80's that tells you nitrox will kill you and to avoid its use. Current, modern information is always a good thing - even if you are not trained/ready to use it. Books can get dated quickly - especially when talking about mixes.

In the current mainstream tec environment where more and more divers go tec, knowing about mixes other than recreational mixes is important. It goes back to the idea of identifying what you are using. Not all nitrox tanks have bumper stickers like PADI claims. For a while, you could find a tank in my garage that looked like any other 80 except for the DIN valve and duck tape on the crown (contents). If you used it - it had around 1300psi of 18/45 trimix in it.

So in that spirit - here is more info that goes WAY beyond the original scope.

Argon - either pure or mixed with 02/air to make it normoxic in case someone tries to breathe it, is used in pony bottle sized tanks by dry suit divers for inflation. Most bottles are label argon. Note I said most, not all.

Helium - Mixed either with O2 (heliox) or o2/n2 (trimix) is used by many divers for deepish dives. IANTD has 2 sport (rec) level classes using hyperoxic trimix to standard rec depths (advanced version goes to 150 though and has limited deco allowed). This mean trimix has gone recreational. Other divers take this as deep as 1000' feet. (CCR's) I personally would go to 250'ish in the right circumstances.

Neon - Mixed with 02 to make NeOx - Used in mostly military ultra deep diving. Its very expensive but has properties similar to He without the HPNS symptoms past 600' or so. The only references I have ever seen to this use and its tables was from military reports in CCR's. Take it for 2nd hand info as I didn't see much.

Hydrogen - Mixed with very low O2 percentages to do ultra deep dives in the 1000-2000' range. This is used in mostly commercial diving. The tables used are trade secrets if that tells you anything. This is used mostly in saturation diving.

See - just mentioning that many divers use 100% o2 can open a really big can of worms - next thing you know, we'll have divers stealing Neon lights to home brew NeOx just to fit in!

bigman241
01-14-2010, 19:50
Book do not get dated around here. Dam college keeps switching books on us. They switched our history book changed the cover and added a few pages. The lady in the bookstore said they where up dated. How in the **** can you up date a book about us history during the 1500 to 1860s. What did they found some other died guy.
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.




It would be my understanding that you have to have special regs. and hoses and have your insurance paid up. :smilie39::smilie39::smilie39:

Again, you glean this expert opinion from?!?!?!? Does it have higher risks? Sure, but so does regular Nitrox.



Apparently, gleaned from the all knowing oracle Wikipedia :smilie39:

First of all this thread was started by brojack17 who only has 21 dives so a lot of what I posted was for his behalf.
Most of my information came from my training manual: "NITROX DIVING, a manual for Recreational Nitrox Scuba Divers, By Fred Calhoun PE, PDIC International.

Another reason not to post that you are using 100% o2 is we also have people reading this posts such as bigman241 who has not even had a regulator in his mouth, he has suggested just breathing from a garden hose, and now he may get the idea that he might just take a o2 tank from his local welding supply shop under water.

I went to the Wikipedia page because someone had stated that "All AIR is NITROX" The Wikipedia page confirmed that he was correct, all AIR is NITROX! But this is a Diving forum so we should use Diving terms. In diving NITROX us a blending of o2 and AIR.
I've been on dives, and I'm sure that you have also where someone makes a statement that their tank is Oxygen, my wife sometimes refers to it as OXYGEN, their statement was somewhat correct it is 20% Oxygen, But in Diving we call it AIR, and we don't call a tank of AIR NITROX.

I made a statement about special regs for 100% o2. My training manual states that o2 content greater than 40% must be cleaned or Oxygen service. It also states; "that some (cylinders, valves and regulators) are not Oxygen compatible".
In my Training Manual it does not go higher then 40%
So in my humble opinion NITROX 22% to 40% is Recreationa and 41% to 100% is teck.

The only caveat is that this is a forum for all divers. I have a PADI book from the late 80's that tells you nitrox will kill you and to avoid its use. Current, modern information is always a good thing - even if you are trained/ready to use it. Books can get dated quickly - especially when talking about mixes.

In the current mainstream tec environment where more and more divers go tec, knowing about mixes other than recreational mixes is important. It goes back to the idea of identifying what you are using. Not all nitrox tanks have bumper stickers like PADI claims. For a while, you could find a tank in my garage that looked like any other 80 except for the DIN valve and duck tape on the crown (contents). If you used it - it had around 1300psi of 18/45 trimix in it.

So in that spirit - here is more info that goes WAY beyond the original scope.

Argon - either pure or mixed with 02/air to make it normoxic in case someone tries to breathe it, is used in pony bottle sized tanks by dry suit divers for inflation. Most bottles are label argon. Note I said most, not all.

Helium - Mixed either with O2 (heliox) or o2/n2 (trimix) is used by many divers for deepish dives. IANTD has 2 sport (rec) level classes using hyperoxic trimix to standard rec depths (advanced version goes to 150 though and has limited deco allowed). This mean trimix has gone recreational. Other divers take this as deep as 1000' feet. (CCR's) I personally would go to 250'ish in the right circumstances.

Neon - Mixed with 02 to make NeOx - Used in mostly military ultra deep diving. Its very expensive but has properties similar to He without the HPNS symptoms past 600' or so. The only references I have ever seen to this use and its tables was from military reports in CCR's. Take it for 2nd hand info as I didn't see much.

Hydrogen - Mixed with very low O2 percentages to do ultra deep dives in the 1000-2000' range. This is used in mostly commercial diving. The tables used are trade secrets if that tells you anything. This is used mostly in saturation diving.

See - just mentioning that many divers use 100% o2 can open a really big can of worms - next thing you know, we'll have divers stealing Neon lights to home brew NeOx just to fit in!

RogerAg
01-15-2010, 09:58
Book do not get dated around here. Dam college keeps switching books on us. They switched our history book changed the cover and added a few pages. The lady in the bookstore said they where up dated. How in the **** can you up date a book about us history during the 1500 to 1860s. What did they found some other died guy.
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.

People who write History Books only tell you what they want you to know.
For instance they tell you George Washington was the first President of the United States of America, I think he was the 7th or 8th.

I understand that as times change so does how we do and understand things.
When I was in the Army I used Shower Shoes, they became Thongs, now they are Flip Flops.

I you are to review some of my posts on the Cobra 2, you will see a somewhat heated discussion on "2 gas switching" One person said that it is done underwater and I was saying that it is on the surface. I have come to the understanding that he may be MORE correct than I am. But I did not know where I got that Stupid Idea, that is until I reread My NITROX manual. It states "2 gas switching" is done during the "surface interval"

So what we think we know, may not be that much!

a22shady
01-16-2010, 19:12
depends on the dive and if i am in the mood to spend the extra money. Some dives are not worth it. For me personally. If i am only goin to be 30-45 doesnt make much sense to spend the additional

Splitlip
01-17-2010, 08:20
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.


Careful. You are getting information overload today.

The use of (hyperoxic :smiley2:) nitrox actually places additional limits on your max depth compared to (normoxic) air. Remember, nitrox is oxygen enriched air. The air you breath now is 21% 02. The most common nitrox mix where I am is 36% oxygen. We can stay down longer than with "air" and have shorter surface intervals, but have shallower maximum operating depth (MOD)

Oxygen is toxic to the body if body at increased pressures. How quickly it becomes toxic in scuba dive depends on the percentage in the tank and the depth.

RogerAg
01-17-2010, 12:07
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.


Careful. You are getting information overload today.

The use of (hyperoxic :smiley2:) nitrox actually places additional limits on your max depth compared to (normoxic) air. Remember, nitrox is oxygen enriched air. The air you breath now is 21% 02. The most common nitrox mix where I am is 36% oxygen. We can stay down longer than with "air" and have shorter surface intervals, but have shallower maximum operating depth (MOD)

Oxygen is toxic to the body if body at increased pressures. How quickly it becomes toxic in scuba dive depends on the percentage in the tank and the depth.

Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

What Iím saying is a simple answer to something that is way more complicated, and you really need to take a course on NITROX.
People that go DEEP, and STAY LONGER take two tanks with them. They may have a AIR TANK and a NITROX tank lets say 36% and your MOD is 1.4. You can not dive below 95 feet on 36% so below that depth you breath off the tank on your back which could be AIR (lets not get into other gasses). At or above 95 feet you do one of two things.
1. You leave the NITROX tank hanging on a Anchor or buoy line. or
2. You take the NITROX tank with you.
Each has good and bad points.
#1 means you don't have to carry that NITROX tank with you everywhere you go. You will use up a lot of AIR just dragging the extra tank. But and this is a big BUT, if you get turned around and can't find the NITROX tank on the way back then you might be in trouble.
#2 Means you drag the tank with you for the whole dive, however all you have to do is get above 95 feet and you can start breathing off it.

At that time you will have to do different dive tables, I hope your good at Math. Or you get a good Dive Computer that allows for "2 gas switching" such as the Cobra 2 or 3. (See the posts of the Cobra 2).
You pre-set the Cobra 2 at MIX 2 "ON" then set it for Mix 1 21% and Mix 2 at 36%. You then start your dive on MIX 1 and, When you come up from your deep dive to 95 feet or less you then start breathing off your NITROX tank and switch your dive computer to MIX 2.

Now that said you also have to worry about decompression. If you go down to 140 feet on AIR which is the max for my training AOW, you can stay down for 10 minutes, (But your a big guy so you might be out of AIR if you stay at 140 feet for 10 minutes). If you stay longer then 10 minutes then you are going into Deco which is not in my AOW training. If you go into Deco then you will have to do a Decompression as well as the regular 3 minute safety stop, near the surface . Lets say you stay at 140 feet for 25 minutes (which might allow you to see the inside of a Decompression Chamber), you will have to do a decompression stop at 20 or so feet for 2 minutes and anther stop (my table says 10 feet) for 14 minutes. Thats about 16 minutes to decompress and 3 minutes safety stop for a total of 19 minutes. And your a big guy to start with, which means you probably will not have that much AIR. Get DAN dive insurance so you wont have to pay for the Decompression Chamber, I understand its expansive.

This is where NITROX will help. When you began to take in the NITROX above 95 feet your Deco stop time will become less. How much less, I don't have a clue because Deco Diving in not in the AOW training.

The Cobra 3 will help you plan these deep dives on your home computer because it connects to USB. I can't do it with my Cobra 2 on my Macintosh because the Cobra 2 does not use USB and is not computable with my Macintosh.

What you really need to do is stop thinking about going deep until you get the training and some dives under you belt.

ZKY
01-17-2010, 12:26
I dive air at home because no dive shops in my area have banked nitrox. I suppose I could get my own 02 tank and do partial pressure fills but I don't want to have to 02 clean everything. On dive boats I like using their banked 32% for as many dives as we do in a day.
If I go to Monterey to dive they have banked nitrox at some of the shops so I'll get a fill.
Over 90% of my diving is on air.

in_cavediver
01-17-2010, 16:12
Bigman,

THe moral is recreational Nitrox requires some training to use - not much but some. The key points are how to calculate PO2's, MOD's based on PO2, O2 limits and Equivalent Air depths (EAD's). The cliff notes version is max PO2 is 1.4 for rec diving, use the NOAA exposure tables to prevent Oxtox from cumulative O2 exposure and make sure to either use tables for the mix you use or use the EAD method for air tables.

As for multiple mixes - Roger got some of it right but its WAY beyond the scope of his training. There is a lot more to decompression diving than just following tables. It creates a cieling above you and therefore you must plan to solve every problem underwater.

jj1987
01-17-2010, 23:54
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.


Careful. You are getting information overload today.

The use of (hyperoxic :smiley2:) nitrox actually places additional limits on your max depth compared to (normoxic) air. Remember, nitrox is oxygen enriched air. The air you breath now is 21% 02. The most common nitrox mix where I am is 36% oxygen. We can stay down longer than with "air" and have shorter surface intervals, but have shallower maximum operating depth (MOD)

Oxygen is toxic to the body if body at increased pressures. How quickly it becomes toxic in scuba dive depends on the percentage in the tank and the depth.

Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

What Iím saying is a simple answer to something that is way more complicated, and you really need to take a course on NITROX.
People that go DEEP, and STAY LONGER take two tanks with them. They may have a AIR TANK and a NITROX tank lets say 36% and your MOD is 1.4. You can not dive below 95 feet on 36% so below that depth you breath off the tank on your back which could be AIR (lets not get into other gasses). At or above 95 feet you do one of two things.
1. You leave the NITROX tank hanging on a Anchor or buoy line. or
2. You take the NITROX tank with you.
Each has good and bad points.
#1 means you don't have to carry that NITROX tank with you everywhere you go. You will use up a lot of AIR just dragging the extra tank. But and this is a big BUT, if you get turned around and can't find the NITROX tank on the way back then you might be in trouble.
#2 Means you drag the tank with you for the whole dive, however all you have to do is get above 95 feet and you can start breathing off it.

At that time you will have to do different dive tables, I hope your good at Math. Or you get a good Dive Computer that allows for "2 gas switching" such as the Cobra 2 or 3. (See the posts of the Cobra 2).
You pre-set the Cobra 2 at MIX 2 "ON" then set it for Mix 1 21% and Mix 2 at 36%. You then start your dive on MIX 1 and, When you come up from your deep dive to 95 feet or less you then start breathing off your NITROX tank and switch your dive computer to MIX 2.

Now that said you also have to worry about decompression. If you go down to 140 feet on AIR which is the max for my training AOW, you can stay down for 10 minutes, (But your a big guy so you might be out of AIR if you stay at 140 feet for 10 minutes). If you stay longer then 10 minutes then you are going into Deco which is not in my AOW training. If you go into Deco then you will have to do a Decompression as well as the regular 3 minute safety stop, near the surface . Lets say you stay at 140 feet for 25 minutes (which might allow you to see the inside of a Decompression Chamber), you will have to do a decompression stop at 20 or so feet for 2 minutes and anther stop (my table says 10 feet) for 14 minutes. Thats about 16 minutes to decompress and 3 minutes safety stop for a total of 19 minutes. And your a big guy to start with, which means you probably will not have that much AIR. Get DAN dive insurance so you wont have to pay for the Decompression Chamber, I understand its expansive.

This is where NITROX will help. When you began to take in the NITROX above 95 feet your Deco stop time will become less. How much less, I don't have a clue because Deco Diving in not in the AOW training.

The Cobra 3 will help you plan these deep dives on your home computer because it connects to USB. I can't do it with my Cobra 2 on my Macintosh because the Cobra 2 does not use USB and is not computable with my Macintosh.

What you really need to do is stop thinking about going deep until you get the training and some dives under you belt.
What you need to do is stop posting that a dive computer is what you need for deco diving. Lost/failed deco gas, rock bottom, and other considerations need to be taken into place. A dive computer serves very little purpose on a deco dive anyways, and even on recreational dives I think the downsides to computers far outweigh any benefits.

Smashee
01-18-2010, 00:35
Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

Or stay at the SAME depth & time with an increased SAFETY MARGIN.

Scuba Pete
01-18-2010, 10:05
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.


Careful. You are getting information overload today.

The use of (hyperoxic :smiley2:) nitrox actually places additional limits on your max depth compared to (normoxic) air. Remember, nitrox is oxygen enriched air. The air you breath now is 21% 02. The most common nitrox mix where I am is 36% oxygen. We can stay down longer than with "air" and have shorter surface intervals, but have shallower maximum operating depth (MOD)

Oxygen is toxic to the body if body at increased pressures. How quickly it becomes toxic in scuba dive depends on the percentage in the tank and the depth.

Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

What Iím saying is a simple answer to something that is way more complicated, and you really need to take a course on NITROX.
People that go DEEP, and STAY LONGER take two tanks with them. They may have a AIR TANK and a NITROX tank lets say 36% and your MOD is 1.4. You can not dive below 95 feet on 36% so below that depth you breath off the tank on your back which could be AIR (lets not get into other gasses). At or above 95 feet you do one of two things.
1. You leave the NITROX tank hanging on a Anchor or buoy line. or
2. You take the NITROX tank with you.
Each has good and bad points.
#1 means you don't have to carry that NITROX tank with you everywhere you go. You will use up a lot of AIR just dragging the extra tank. But and this is a big BUT, if you get turned around and can't find the NITROX tank on the way back then you might be in trouble.
#2 Means you drag the tank with you for the whole dive, however all you have to do is get above 95 feet and you can start breathing off it.

At that time you will have to do different dive tables, I hope your good at Math. Or you get a good Dive Computer that allows for "2 gas switching" such as the Cobra 2 or 3. (See the posts of the Cobra 2).
You pre-set the Cobra 2 at MIX 2 "ON" then set it for Mix 1 21% and Mix 2 at 36%. You then start your dive on MIX 1 and, When you come up from your deep dive to 95 feet or less you then start breathing off your NITROX tank and switch your dive computer to MIX 2.

Now that said you also have to worry about decompression. If you go down to 140 feet on AIR which is the max for my training AOW, you can stay down for 10 minutes, (But your a big guy so you might be out of AIR if you stay at 140 feet for 10 minutes). If you stay longer then 10 minutes then you are going into Deco which is not in my AOW training. If you go into Deco then you will have to do a Decompression as well as the regular 3 minute safety stop, near the surface . Lets say you stay at 140 feet for 25 minutes (which might allow you to see the inside of a Decompression Chamber), you will have to do a decompression stop at 20 or so feet for 2 minutes and anther stop (my table says 10 feet) for 14 minutes. Thats about 16 minutes to decompress and 3 minutes safety stop for a total of 19 minutes. And your a big guy to start with, which means you probably will not have that much AIR. Get DAN dive insurance so you wont have to pay for the Decompression Chamber, I understand its expansive.

This is where NITROX will help. When you began to take in the NITROX above 95 feet your Deco stop time will become less. How much less, I don't have a clue because Deco Diving in not in the AOW training.

The Cobra 3 will help you plan these deep dives on your home computer because it connects to USB. I can't do it with my Cobra 2 on my Macintosh because the Cobra 2 does not use USB and is not computable with my Macintosh.

What you really need to do is stop thinking about going deep until you get the training and some dives under you belt.

I think you need to stop posting about subjects that are above your training level. I don't know much on this subject but i do know that while you are correct in some of the items. You are incorrect in others. Deep diving requires proper training, planning and specialized equipment. IMHO a deep dive starts at 100'. Just because you have AOW does not mean you are an advanced diver and are able to go to 140'. Nevermind the fact that 140' is a technical dive and no longer a recreational type dive.

navyhmc
01-18-2010, 12:34
Maybe we should change the term from Nitrox/Ean to Normoxic and Hyperoxic gasses...that's essentially what it is....

in_cavediver
01-18-2010, 14:10
Instead of picking on Roger - he means well and we should welcome him, I will try to correct a few of his errors.

First - if you go below 130' you are venturing into the tec realm. Rec diving by the RTSC (consortium of most agencies) defines rec as 0-130'. The most common delinetions are 60' for OW, 100' for AOW and 130 for deep (rec cert).

Now, for nitrox - it is used to go deeper and stay longer, sometimes as a bottom gas, sometimes as a deco gas. For bottom mixes, the max PO2 is at most 1.4. Many tec divers tend to push this back to 1.2-1.3 and save the o2 exposure for deco. For the deco gases, a PO2 of 1.6 is most commonly used. This assumes a resting state rather than a working state.

As for how gas is dealt with, in OW most divers keep it on them, slung on the left side. In overheads such as cave diving, it is most commonly dropped on the way in to reduce drag.

Now for the biggie - planning. It takes more than a dive computer to properly plan a tec dive. You have to address several things that a dive computer simply cannot do. First, you have to plan the profile you want to dive. This could be simply 20-25 minutes at 150'.

Then, you take the profile you want to dive and apply a decompression model of you choice to get tables. There are a lot of choices for which decompression model to chose with the key deciding factor for most being expierence with one. I personally like the Beuhlmann with Pyle stops or aggressive gradient factors applied. My body tends to agree. Other may like the bubble models or raio deco. Again, there is no right or wrong, only what you and your body like. The way to learn this is with expierence and build up to the profiles you are diving. Only a fool would jump from 100-150' depths to 400' depths without a fair bit of expierence in between.

Once we have the models we like, we can start choosing the gas for the dive. It could be air, nitrox, trimix plus 50/50, 80/20, or 02. You will notice the typical deco gases are high O2 concentrations, 50%, 80% and 100%. This is for several reasons but mainly its because high o2 gases are better at flushing inert gas out than low o2 gases. They also have the benefit of less inert gas to take in. I personally use 100% almost exlusively. Its easiest for me to get and does a great job at 20' and doubles as emergency o2 on the surface.

Last part - starting to calculate the gas needs. We know the depths we want to go, we know the stops we need to do, now we just need to calculate the amount of gas required. (backgas and deco).

Now that the basics of the dive are done, we need to start looking at problems. A couple examples are overstaying dive time, buddies gas failure and a lost deco gas. From this, we figure out how to reserve gas for our buddies (thirds, 1/2 + 200 or whatever gas plan makes the most sense based on the dive - its not always thirds). We also need to look at our tables and make sure we can get up without the deco gas.

If you have read this far - please remember. You need formal training to use this information safely. There are proper procedures for handling emergencies underwater that are are taught in these classes. You also need a lot more equipment as well. A rec diver may use a single reg with a single tank. To do the dive above - you are looking at 3 first stages, 3 second stages, doubles and a deco bottle plus the harness/wing to carry it all.

Once you hit this level of diving, the surface is no longer an option. If interested, please take the formal training. This is not the area to 'self train' yourself.

ssmdive
01-18-2010, 17:18
[quote=Aquatrax;359358]

First of all this thread was started by brojack17 who only has 21 dives so a lot of what I posted was for his behalf.

Most of my information came from my training manual: "NITROX DIVING, a manual for Recreational Nitrox Scuba Divers, By Fred Calhoun PE, PDIC International.

Then give them REAL information.... I seriously doubt that the training manual: NITROX DIVING, a manual for Recreational Nitrox Scuba Divers, By Fred Calhoun PE, PDIC International stated, "100% was dead".


Another reason not to post that you are using 100% o2 is we also have people reading this posts such as bigman241 who has not even had a regulator in his mouth, he has suggested just breathing from a garden hose, and now he may get the idea that he might just take a o2 tank from his local welding supply shop under water.

Then give him GOOD, REAL, TRUTHFUL information not BS, half-truths, and voodoo speak. All your credibility goes out the window the first time he see's or hears of someone walking into the water with a 100% bottle.


I've been on dives, and I'm sure that you have also where someone makes a statement that their tank is Oxygen, my wife sometimes refers to it as OXYGEN, their statement was somewhat correct it is 20% Oxygen, But in Diving we call it AIR, and we don't call a tank of AIR NITROX.

And you claiming that 100% O2 is "dead"... is the EXACT same incorrect BS as the people you are bitching about claiming their air tanks are "Oxygen".


I made a statement about special regs for 100% o2. My training manual states that o2 content greater than 40% must be cleaned or Oxygen service.

I pulled a regular reg out of a box and used it for 100% deco this weekend.

Again, the difference of you reading something in a book and others actually having the experience.


In my Training Manual it does not go higher then 40%
So in my humble opinion NITROX 22% to 40% is Recreationa and 41% to 100% is teck.

Then maybe it would be a good idea to not give information you don't honestly know?


Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

Not correct at all. Nitrox LIMITS your depth due to the PPO2 issues.
I have taken regular air to 200 feet... I could not have done that with anything that you are calling Nitrox.

Air's MOD is 218 feet.
32%'s MOD is 132 feet.

Nitrox is used to increase your bottom times, within recreational depths, without building as much of a deco commitment.

To *safely* go deep you need LESS O2, not more.

For ~200 feet you should have around 19% O2 and 30% Helium.


Lets say you stay at 140 feet for 25 minutes (which might allow you to see the inside of a Decompression Chamber)

Again, total nonsense. I did 150 feet deep for about an hour and I didn't see a chamber. I DID have to spend a BUNCH of time sitting at 20 feet with my non O2 cleaned regulator attached at one end to a 100% O2 bottle and the other my mouth.

The problem with giving advice about topics that you don't know is it hurts more than it helps. In my other hobbies I hold several instructor ratings and it takes more time to unlearn internet experts than just to give them good information.

j1j2j38
01-18-2010, 17:24
I use nitrox if available and the same price. If not available then obviously air. If not the same price then it depends on the dive profile but would usually pay 25% more or so for nitrox.

mitsuguy
01-18-2010, 18:21
I've been on dives, and I'm sure that you have also where someone makes a statement that their tank is Oxygen, my wife sometimes refers to it as OXYGEN, their statement was somewhat correct it is 20% Oxygen, But in Diving we call it AIR, and we don't call a tank of AIR NITROX.

And you claiming that 100% O2 is "dead"... is the EXACT same incorrect BS as the people you are bitching about claiming their air tanks are "Oxygen".


I made a statement about special regs for 100% o2. My training manual states that o2 content greater than 40% must be cleaned or Oxygen service.

I pulled a regular reg out of a box and used it for 100% deco this weekend.

Again, the difference of you reading something in a book and others actually having the experience.


In my Training Manual it does not go higher then 40%
So in my humble opinion NITROX 22% to 40% is Recreationa and 41% to 100% is teck.

Then maybe it would be a good idea to not give information you don't honestly know?


Splitlip is totaly correct, however I noticed that nobody rally explained NITROX to you in the way you may understand it. And the reason for that is you want to go DEEP, and STAY LONGER.

Not correct at all. Nitrox LIMITS your depth due to the PPO2 issues.
I have taken regular air to 200 feet... I could not have done that with anything that you are calling Nitrox.

Air's MOD is 218 feet.
32%'s MOD is 132 feet.

Nitrox is used to increase your bottom times, within recreational depths, without building as much of a deco commitment.

To *safely* go deep you need LESS O2, not more.

For ~200 feet you should have around 19% O2 and 30% Helium.


Lets say you stay at 140 feet for 25 minutes (which might allow you to see the inside of a Decompression Chamber)

Again, total nonsense. I did 150 feet deep for about an hour and I didn't see a chamber. I DID have to spend a BUNCH of time sitting at 20 feet with my non O2 cleaned regulator attached at one end to a 100% O2 bottle and the other my mouth.

The problem with giving advice about topics that you don't know is it hurts more than it helps. In my other hobbies I hold several instructor ratings and it takes more time to unlearn internet experts than just to give them good information.

Alright man, you call yourself an instructor and you don't follow the general safe rules and practices that are put into play for safety reasons... Please tell me you do this in whatever you do profess to teach... If not, I hope no one takes a course from you, seriously.

Now, I do completely agree about the 100% comments made above and that 100% o2 won't kill you (done properly)... HOWEVER!

Using a non-O2 cleaned reg on pure O2 is just outright dangerous! Especially if the manufacturer did not use O2 compatible lubricants. Do you know which ones do? I don't have a clue, and except for O2 designed regs, have not found one that specifically states it uses O2 compatible lube... then, if there is a contaminant with some sort of hydrocarbon (even an oily fingerprint), there is a chance for a fire! Not exactly what I would want to be breathing when I am doing my mandatory deco stop...

You should also clarify on your MOD's for nitrox and air... those are at 1.6 PO2, which is considered by many to be a little on the risky side. 1.4 is a more commonly agreed upon, working PO2... If I want to be picky, saying those are safe at 1.6 is like saying you die on 100% O2 - it's only accurate if other circumstances are met...

I hate to call BS on your an hour at 150 feet, but I am going to anyways... not that it can't be done, but because the way you describe the dive doesn't follow the rest of your post with very specific information...

On air, spending 60 minutes at 150 feet, you are going to have one hour and 52 minutes of deco obligation, with deep stops starting at 90 feet... using a very moderate .5 SAC, you would need 171 cu ft of air at your max depth, then an additional 86 cu ft to travel from 150 ft to 20 ft, where you should switch to your 100% deco gas, where you still need to spend 15 minutes, then another 26 minutes at 10 feet, where you will consume approximately 29 cu ft of pure O2... Calculations courtesy of deco-planner... sure, it can be done, its just a matter of how safely it is / was done...

ssmdive
01-18-2010, 19:39
Alright man, you call yourself an instructor and you don't follow the general safe rules and practices that are put into play for safety reasons... Please tell me you do this in whatever you do profess to teach... If not, I hope no one takes a course from you, seriously.I don't "claim" to be an instructor... I am, and several organizations agree.... I actually said "in other hobbies", but I should have also included a Fortune 500 company as well.

You seem to be just trolling for an argument. Since you didn't add anything but friction here.


Using a non-O2 cleaned reg on pure O2 is just outright dangerous! Especially if the manufacturer did not use O2 compatible lubricants. Do you know which ones do? I don't have a clueClearly it is not dangerous... Yaknow since I did it and my mouth didn't burst into flames. *Could* it be dangerous? Sure, but just because YOU don't know what regs are fine and which are not does not mean others don't.


there is a chance for a fire! Not exactly what I would want to be breathing when I am doing my mandatory deco stop...I guess you are the type of diver that does not bother to check their equipment and just jumps in the water? Again, just because you don't know or test these things does not mean others don't know or don't test these things.

FYI, the reg in question was imported into the States by a friend.... So I knew about it, who built it, how it was built, and what it was built with. Still, it is not "certified for O2 service".... Just a regular reg.


You should also clarify on your MOD's for nitrox and air... those are at 1.6 PO2, which is considered by many to be a little on the risky side.1. I did call them MOD's and I mentioned them as LIMITS. Most consider LIMITS to be maximums.

2. This is not a class, and as I stated I am not a SCUBA instructor.


I hate to call BS on your an hour at 150 feet, but I am going to anyways... not that it can't be done, but because the way you describe the dive doesn't follow the rest of your post with very specific information...So my internet dive log was not EXACT... I did a thing people call generalization.


using a very moderate .5 SAC, you would need 171 cu ft of air at your max depth, then an additional 86 cu ft to travel from 150 ft to 20 ftWell lets see.... I have double HP 133's. And with a 3600 fill I should have about 270 feet of gas (might want to check my math this is just a WAG).....Not including deco bottles (50% AL80 and 100% AL40)... I'd bet you will find I had enough gas.


where you should switch to your 100% deco gas, where you still need to spend 15 minutes, then another 26 minutes at 10 feet, where you will consume approximately 29 cu ft of pure O2But you are assuming that my only deco gas was 1 O2 bottle. You are ignoring 50% bottles that can be used at 70 feet.

You also read my "I did 150 feet deep for about an hour" and read it as a flat one hour at exactly 150 feet.... Truth is my max depth was 154 feet and I didn't just sit at the low point and play tic-tac-toe in the silt.

You wanna just whip out our peckers and a measuring tape? It might be faster.

in_cavediver
01-18-2010, 20:43
OK everyone - settle down. Its not that big of a deal.

Yes you can easily do a dive to 150ft for 60min with the right deco gases. You'll be in the water a while but a cave filled set of 104's or 121's + 50/50 and o2 and its not that bad. (for those at home, my cave filled 104's at 3800 have around 300cft, the 50/50 would be in an 80 and the o2 in a 45 filled to 3000 or 51cft of o2). It would be even eaiser to do with a CCR.

Roger was a little beyond his training and made some mistakes in his explanation but hopefully he learned a little about what it takes from people trained to do the dives. There is no reason to be nasty.

Mitsguy is also right about the O2 clean regs. 100% does require proper precautions to be taken. Dive Rite used to ship thier regs 02 ready right out of the box. Many other have o2 regs or kits for cleaning thier regs to meet o2 standards. It is irresponsible to suggest any old reg is OK.

I'll be the first to say HP o2 handling is first and foremost all about good handling techniques. Cleanliness is second. With great technique, a 'dirty' bottle can be filled safely. With poor technique, the cleanest bottle can still be lit on fire. At these pressures, the metals themselves can become fuels. Take it seriously and take good precautions, which includes good technique and good cleanliness.

mitsuguy
01-18-2010, 22:45
I don't "claim" to be an instructor... I am, and several organizations agree.... I actually said "in other hobbies", but I should have also included a Fortune 500 company as well.

You seem to be just trolling for an argument. Since you didn't add anything but friction here.


No, not trolling for an argument, just simply stating the facts that if you are willing to break what we call standards because you simply think it's ok, then what are you going to do when it comes to teaching something??? I am an instructor in SCUBA diving and have many other certs that apply here as well, namely gas blending.



Clearly it is not dangerous... Yaknow since I did it and my mouth didn't burst into flames. *Could* it be dangerous? Sure, but just because YOU don't know what regs are fine and which are not does not mean others don't.


can you provide a list of which ones are ok, and which ones aren't? that would be AMAZING! In order for a reg to be suitable for use in a high O2 environment, it has to have a few things - 1) it has to be designed for O2 use 2) it has to be built with O2 compatible materials and 3) it has to be cleaned properly for O2 use... There are a few regs that meet this out of the box, but, the only ones that are guaranteed to meet this are the ones that specifically show it in the literature, for instance: Dive Rite O2 Clean Deco Regulator Setup reviews and discounts, Dive Rite (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=DiveRiteO2DecoSetup) which states: "Using oxygen compatible materials and assembly processes that are today industry standard, the Dive Rite O2 Deco regulator setup is suitable for 100 percent oxygen use at gas pressures up to 3000 psi." However, another reg that one might think is suitable, the manufacturer actually claims is NOT suitable for anything over 50%: Poseidon Xstream Duration 90 Regulator reviews and discounts, Poseidon (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=PoseidonDuration) which says "Up to 50% oxygen can be used in the Duration that is Oxygen engineered, Oxygen compatible, Oxygen clean, Oxygen approved; hence the color-coding green for Nitrox in both the first and the second stage"


I guess you are the type of diver that does not bother to check their equipment and just jumps in the water? Again, just because you don't know or test these things does not mean others don't know or don't test these things.

FYI, the reg in question was imported into the States by a friend.... So I knew about it, who built it, how it was built, and what it was built with. Still, it is not "certified for O2 service".... Just a regular reg.

Alright, since some people test these things, I would like to know the proper procedure for testing if a reg that is not supposed to be O2 compatible, actually is O2 compatible... can i just press the purge button and so long as fire doesn't shoot out, I'm good? Seriously, what type of O-rings were used? What type of metal was used, what type of lubrication was used? All of these things are important. Was the reg built as to lessen the amount of friction made when the piston or diaphragm moves? Who built the reg you are talking about? Is this not a name brand, because you are jumping around with lots of not adding information...



You should also clarify on your MOD's for nitrox and air... those are at 1.6 PO2, which is considered by many to be a little on the risky side.1. I did call them MOD's and I mentioned them as LIMITS. Most consider LIMITS to be maximums.

2. This is not a class, and as I stated I am not a SCUBA instructor.


As you clearly stated, people should not be giving out misinformation on the boards. You said that just because 100% O2 is not deadly on every dive in every circumstance, that someone above should not say that. That is OK, but I am going to hold you to the same level. Do you know what MOD means? Maximum Operating Depth. Limit = Maximum, in your words. You can choose to disagree, but every recreational agency recommends a 1.4 PO2 MOD, with a 1.6 PO2 MOD as a contingency just in case. You should dive within your 1.4 LIMIT, but if you surpass it a little, you still need to track O2 exposure, so 1.6 is still on the charts. As someone already mentioned, the tech guys like to limit O2 exposures down to 1.2ish so that they can use high O2 exposures for deco stuff, up to around 1.6 PO2. You will only find them using this high of a PO2 for deco when no work is being done, ie hanging on a line / mid water, not swimming around...


You also read my "I did 150 feet deep for about an hour" and read it as a flat one hour at exactly 150 feet.... Truth is my max depth was 154 feet and I didn't just sit at the low point and play tic-tac-toe in the silt.

Um, when you calculate deco time and planning like that, you calculate it all as a square profile dive - time starts from the beginning of your descent, then, on your way back, you go from bottom time, to beginning of deco time / stops... so, if your maximum depth was 154 feet, you calculate the whole beginning portion of your dive as 154 feet. Unless you were just winging it with a gas switching dive computer, which is potentially dangerous without a preplanned table to begin with.


You wanna just whip out our peckers and a measuring tape? It might be faster.

No, I'd prefer the misinformation to stop - you have somewhat of a superiority complex going on... you are the type that gets hurt (and gets others hurt) while diving - I hear it all day long at the shop - "ah thats the way I've always done it and I've been ok" or "I'm still here aren't I"

Those types of attitudes are the ones we read about in the "lessons for life" sections of magazines... I just want you and everyone on this board to be safe and practice good skills and judgement...

Splitlip
01-19-2010, 07:21
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.


Careful. You are getting information overload today.

The use of (hyperoxic :smiley2:) nitrox actually places additional limits on your max depth compared to (normoxic) air. Remember, nitrox is oxygen enriched air. The air you breath now is 21% 02. The most common nitrox mix where I am is 36% oxygen. We can stay down longer than with "air" and have shorter surface intervals, but have shallower maximum operating depth (MOD) *

Oxygen is toxic to the body if body at increased pressures. How quickly it becomes toxic in scuba dive depends on the percentage in the tank and the depth.

I tried to make this simple, but I see by some replies I was not clear.

*
Maximum depth for air for example is 218ft. Maximum depth for 36% Nitrox is 113 ft more are less. (PO2 of 1.6. There are variables you will learn. I usually plan for a more conservatrive PO2 of 1.4)

Bottom line, benefits of (hyperoxic) nitrox is NOT for "deeper" diving.

ssmdive
01-19-2010, 07:52
No, I'd prefer the misinformation to stop - you have somewhat of a superiority complex going on... you are the type that gets hurt (and gets others hurt) while diving - I hear it all day long at the shop - "ah thats the way I've always done it and I've been ok" or "I'm still here aren't I"

Those types of attitudes are the ones we read about in the "lessons for life" sections of magazines... I just want you and everyone on this board to be safe and practice good skills and judgement...


Again, just because YOU don't know how to check if something is O2 safe does not mean others don't. Just because YOU don't know something does not mean others don't. Yes, if you can't tell the difference, don't try it.

You claiming that others have a superiority complex drives the irony scale off the chart! You came (and clearly still are) looking for a fight.

So, do you want to measure our cocks or not?

And BTW... You can plan deco schedules for multiple depth profiles... You have to do more than plug some numbers into a dive program and hope for the best.

So... It is pretty clear you are just looking for a fight.. It is also clear you are the type that has to win some stupid internet argument.... You can have the last word... I plan on just ignoring you.

dkh6070
01-19-2010, 08:28
It's getting heated in here. I'll turn on the fan........

mitsuguy
01-19-2010, 11:57
No, I'd prefer the misinformation to stop - you have somewhat of a superiority complex going on... you are the type that gets hurt (and gets others hurt) while diving - I hear it all day long at the shop - "ah thats the way I've always done it and I've been ok" or "I'm still here aren't I"

Those types of attitudes are the ones we read about in the "lessons for life" sections of magazines... I just want you and everyone on this board to be safe and practice good skills and judgement...


Again, just because YOU don't know how to check if something is O2 safe does not mean others don't. Just because YOU don't know something does not mean others don't. Yes, if you can't tell the difference, don't try it.

You claiming that others have a superiority complex drives the irony scale off the chart! You came (and clearly still are) looking for a fight.

So, do you want to measure our cocks or not?

And BTW... You can plan deco schedules for multiple depth profiles... You have to do more than plug some numbers into a dive program and hope for the best.

So... It is pretty clear you are just looking for a fight.. It is also clear you are the type that has to win some stupid internet argument.... You can have the last word... I plan on just ignoring you.

You keep telling us that all these things are possible, but not a word of how to do them... Not in any material, or any book have I ever found a practical way to test if a regulator is O2 safe or not... I know how to clean them to be, and typically, we can determine whether the materials used in their construction is O2 safe as well, but one thing we can't account for is their design. Ever see O2 cylinders connected in a shop? They use a circular piece of longer tubing just to slow down the particles as that tubing is pressurized... Simple things like this can make the difference between being safe and not. Can you truly test for this in a non-laboratory type environment?

And yes, I know that it is very possible to plan multi level dives, though most divers in the technical realm do NOT do it. You started off with an hour at 150 feet, then it became around an hour, and the max depth was 154 feet, but not all of the dive... Those are two wholly different things. The person you were chastizing said 25 minutes at 140 feet. You said that an hour at 150 feet was possible with deco time... That person was talking about a full 25 minutes spent at 140 feet, then you spew info about 150 feet and that an hour is doable... Your story is so full of holes.

I am not holier than thou, I just know my material and I know where to find all the answers. That doesn't make me better than you or anyone else. What I do do, is I follow the safe guidelines so that I don't get anyone hurt, which obviously you do not. But thats OK, just don't go spewing this info on message boards as fact.

If this was any other board, I would take your challenge to a new high, but I'll keep the comments clean, as I like that about this board in specific.

StreetDoctor
01-19-2010, 13:26
95% of the time I dive 32%

in_cavediver
01-19-2010, 17:23
......
You keep telling us that all these things are possible, but not a word of how to do them... Not in any material, or any book have I ever found a practical way to test if a regulator is O2 safe or not... I know how to clean them to be, and typically, we can determine whether the materials used in their construction is O2 safe as well, but one thing we can't account for is their design. Ever see O2 cylinders connected in a shop? They use a circular piece of longer tubing just to slow down the particles as that tubing is pressurized... Simple things like this can make the difference between being safe and not. Can you truly test for this in a non-laboratory type environment?

Sorry - gotta make a correction here. The circular tubing in fixed bank systems is NOT to account for gas flow. Its to account for physical tank movement without stressing the HP gas connections. A straight tube could break the seal with slight movement of the tanks. In reality, it would be *better* not to have the bends. Bends add friction. Friction adds heat and if you get enough heat, you get fire. Straight, un-impeded connections are always best for HP o2.

Another factor you sometimes see in 'swappable cascades' is the use of premade connections. These are fixed length so you get what you need and then deal with any excess, usually coiled out of the way. Again, not the best case to avoid frictional heating but likely the best option for many shops to give flexibility in connections and tank movement/swapping. The best case is the shortest and straightest possible route with the fewest restrictions along the way for the HP gas. (its also the easiest to keep clean)

As for design of regs - there is very little difference between regs. They are either a piston or diaphram type with some type of HP valve. If the materials are compatable (structure+lube+o-rings) you can be good to go with o2. Some are better than others based on gas flow but since this is the tail end of the line for HP gas flow, its a little less sensitive due to adiabatic cooling of going from HP to LP. Its also less sensitive due to the nature of the demand reg. Its not constantly flowing gas so frictional heat does not build.




And yes, I know that it is very possible to plan multi level dives, though most divers in the technical realm do NOT do it. You started off with an hour at 150 feet, then it became around an hour, and the max depth was 154 feet, but not all of the dive... Those are two wholly different things. The person you were chastizing said 25 minutes at 140 feet. You said that an hour at 150 feet was possible with deco time... That person was talking about a full 25 minutes spent at 140 feet, then you spew info about 150 feet and that an hour is doable... Your story is so full of holes.


Actually - every tec diver plans a profile then does bailouts and contingency plans which include deeper and longer as well as shorter. planning a dive to 150 for 60 min and bailing to the 160' plan for 54min can happen. All it takes is an unforseen issue underwater and you are there.

If I were to plan that dive, I'd have tables for 140, 150 and 160 with times starting at 30 min and going to 70min. I'd also have a table for the 10min bottom time to use if I bailed immediately. I'd have those with and without my deco gases. I'd take all of this, transcribe what I needed to slates and take them with me. I could get it on a couple small slates (or wetnotes)easily enough.

mitsuguy
01-19-2010, 18:03
Sorry - gotta make a correction here. The circular tubing in fixed bank systems is NOT to account for gas flow. Its to account for physical tank movement without stressing the HP gas connections. A straight tube could break the seal with slight movement of the tanks. In reality, it would be *better* not to have the bends. Bends add friction. Friction adds heat and if you get enough heat, you get fire. Straight, un-impeded connections are always best for HP o2.

Another factor you sometimes see in 'swappable cascades' is the use of premade connections. These are fixed length so you get what you need and then deal with any excess, usually coiled out of the way. Again, not the best case to avoid frictional heating but likely the best option for many shops to give flexibility in connections and tank movement/swapping. The best case is the shortest and straightest possible route with the fewest restrictions along the way for the HP gas. (its also the easiest to keep clean)

As for design of regs - there is very little difference between regs. They are either a piston or diaphram type with some type of HP valve. If the materials are compatable (structure+lube+o-rings) you can be good to go with o2. Some are better than others based on gas flow but since this is the tail end of the line for HP gas flow, its a little less sensitive due to adiabatic cooling of going from HP to LP. Its also less sensitive due to the nature of the demand reg. Its not constantly flowing gas so frictional heat does not build.


Hmmm, I was told / instructed that the loops serve both purposes actually. That there may be a slight amount of frictional heat added, but it reduces the amount of particle impingement from the O2 slamming into the next stopping point for it.

The same reason certain regs may be deemed inappropriate for O2 use, the possibility of severe right angles and tight orifices that make this bad as well. On top of questionable design, I'm not sure I've seen many regs that have service kits available with o2 compatible o-rings...



Actually - every tec diver plans a profile then does bailouts and contingency plans which include deeper and longer as well as shorter. planning a dive to 150 for 60 min and bailing to the 160' plan for 54min can happen. All it takes is an unforseen issue underwater and you are there.

If I were to plan that dive, I'd have tables for 140, 150 and 160 with times starting at 30 min and going to 70min. I'd also have a table for the 10min bottom time to use if I bailed immediately. I'd have those with and without my deco gases. I'd take all of this, transcribe what I needed to slates and take them with me. I could get it on a couple small slates (or wetnotes)easily enough.


yup... completely understand... but there are multiple dive profiles made, but not multiple depths on the same dive, which is what the above argument was about...

in_cavediver
01-19-2010, 20:07
yup... completely understand... but there are multiple dive profiles made, but not multiple depths on the same dive, which is what the above argument was about...

That is done too. I have done several dives in cave specifically where I gave myself run times at various depths to cut tables. Robuidoux was one. It has a short couple hundred feet in at 40ish feet before dropping to 140-150'. I planned dives where I planned for a 10 minute swim in at 40', then 20-30 minutes at 150 with the adjusted deco to account for the swim again at 40'.

Its just more complicated to do, not impossible. In the profile I mentioned above, the difference in a few minutes at 40' on the way in was not significant to the deco schedule. I ran differing times to know what the second part of the dive would call for. I knew so long as I didn't overstay excessively that 10 minutes, I would be OK on deco. I could have repeated the process for 80' with similar results. It might not be as clean to where you can pretty much negate the difference on the shallow portion but still extremely doable.

Its these kind of dives that I really have my VR3 for. I can run profiles all day and get a feel for what I ought to do and I have a model my body likes to confirm it with on the real dive. It also helps get me out of a jam if my plans go completely out the window. Grossly overstay a segment of the dive for instance. Without the VR3 - my plan basically involves winging the deco to 20' based on the info I have and know and then staying at 20' as long as my o2 holds out. With the VR3, I have much more information as to how to get out of the water even if the profile is vastly different than I planned.

In either case, doing multi-level decopression diving is more risk than single level (square profile) decompression diving. Its not the different profile that's the problem, its the risk of getting outside the range of your planned profile. (lots easier to do and much harder to interpolaite deco with mulitple levels contributing). The problem is, I like caves and most caves aren't square. I go where the cave goes so I need to know how to plan said dives safely. If the depths/times put me into deco, I want to know how to get out of deco safely - on the fly.

RogerAg
01-21-2010, 17:32
I believe that at the beginning of my post I satated:

What Iím saying is a simple answer to something that is way more complicated, and you really need to take a course on NITROX.

And I sure was right. My statement sure brought a lot of ideaís out into the open.
The reason I posted in the first place was because:

Originally Posted by bigman241
Though off my rant I think it is alittle funny they said it would kill you though now it is about the norm for deeper diving.

Iíve gotten fond of bigman241 and I don't want to see him get into the worse trouble there is for a diver. So to ALL of you that posted after my post, Conservative and Liberal I say; you did a great job of explaining that NITROX is nothing to take for granted and definitely not without training.:smiley20:

jeffgerritsen
02-02-2010, 14:38
It's simple for spouse and I - we are 53, we use 36 percent nitrox, and we don't feel "wiped out" after two or three dives in one day!

Take the nitrox class, watch your MOD, PO2, and cns clock time and you should be fine!

They don't call it "geezer gas" for nothing! :smiley2:

UCFKnightDiver
02-02-2010, 14:48
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

in_cavediver
02-02-2010, 16:02
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

brojack17
02-02-2010, 16:08
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

Free because you have a compressor and fill the tank yourself?

CompuDude
02-02-2010, 19:06
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

Free because you have a compressor and fill the tank yourself?

Free because he has access to his local fire dept's fill station, if memory serves.

mitsuguy
02-02-2010, 19:09
there are many many dives that nitrox is just silly for...

for example - our wall dives... average 65 feet for 20 minutes, then 25 feet for 30 - 40 minutes...

CompuDude
02-02-2010, 19:19
there are many many dives that nitrox is just silly for...

for example - our wall dives... average 65 feet for 20 minutes, then 25 feet for 30 - 40 minutes...

Not silly for people who tire easily and believe in the benefits of Nitrox from a "less tired after the dive" stand point. (just saying, I'm not among them)

Also not silly for people who have increased risk factors and always dive Nitrox to decrease risk.

Just saying. There are few absolutes.

in_cavediver
02-02-2010, 19:54
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

Free because you have a compressor and fill the tank yourself?

Free because he has access to his local fire dept's fill station, if memory serves.

Excellent memory - all it takes is my willingness to get out of bed at 0-dark-thirty to help my fellow man.

Truth be told - buying air would be a lot cheaper in the long run and that's not why I volunteer.

in_cavediver
02-02-2010, 19:56
there are many many dives that nitrox is just silly for...

for example - our wall dives... average 65 feet for 20 minutes, then 25 feet for 30 - 40 minutes...

If I did a week of those dives - i'd still do them on nitrox. I personally believe nitrox best benefit cannot be felt on a single dive. Its the multi-dive multi-day trips where it really shines.

UCFKnightDiver
02-02-2010, 19:56
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

Really? air is about 80% nitrogen, you sure air wont work just fine? Now pure o2, that would be a riot.

in_cavediver
02-02-2010, 19:58
I'm 21 and dive nitrox almost exclusively (32%) nitrox is simply a better gas for diving than air. Air is for tires.

Actually - pure Nitrogen is better in tires that air..........

For me - I dive air a lot because its FREE. Otherwise, I prefer Nitrox if I am paying.

Really? air is about 80% nitrogen, sure air wont work just fine? Now pure o2, that would be a riot.

Yep.

Nitrogen in Tires : Information about Nitrogen Tire Inflation News, Benefits, Generator Dealers, Location Finder & More (http://www.getnitrogen.org/)

UCFKnightDiver
02-02-2010, 20:03
Do you have to pay extra money for nitrogen? Cause air works just fine for me(never got nitrogen in my tires seriously doubt I would see a benefit), sounds like a bit of an industry scam to be honest.

in_cavediver
02-02-2010, 20:08
Do you have to pay extra money for nitrogen? Cause air works just fine for me(never got nitrogen in my tires seriously doubt I would see a benefit), sounds like a bit of an industry scam to be honest.

There is really some potential there but I still run with air in my tires. Something about that shop compressor I have in my garage. If you were a commuter or drove for a living, I can see the greater benefits but for the average joe schmoe driver, its probably as much a feel good measure as a real measured benefit.

CompuDude
02-03-2010, 00:44
Do you have to pay extra money for nitrogen? Cause air works just fine for me(never got nitrogen in my tires seriously doubt I would see a benefit), sounds like a bit of an industry scam to be honest.

If you're a high end race care driver where split seconds count, it can probably make a small difference.

Going from 80% Nitrogen to 100% Nitrogen just isn't going to make a huge difference to your average commuter, though.

I'm not going to trust the "Get Nitrogen Institute" to give me a fair and unbiased opinion on the matter, either.

Cecil, on the other hand: The Straight Dope: Is it better to fill your tires with nitrogen instead of air? (http://www.straightdope.com/columns/read/2694/is-it-better-to-fill-your-tires-with-nitrogen-instead-of-air)

...and Consumer Reports: Consumer Reports Cars Blog: Tires - Nitrogen air loss study (http://blogs.consumerreports.org/cars/2007/10/tires-nitrogen-.html)

...and the New York Times: http://www.nytimes.com/2008/03/09/automobiles/09MOTO.html?_r=1

...and, well, this guy: Nitrogen Filled Tires: a Scam? ę Hot Cup of Joe (http://ahotcupofjoe.wordpress.com/2008/07/05/nitrogen-filled-tires-a-scam/)

...ALL make a LOT more sense when they agree that you'll do better by simply making sure your tires are properly inflated.

If Nitrogen tire fills are free for you (or if you race your high end race car, or drive a semi), then go for it... it's not going to hurt a bit. But don't pay a dime extra.

RogerAg
02-03-2010, 09:33
Do you have to pay extra money for nitrogen? Cause air works just fine for me(never got nitrogen in my tires seriously doubt I would see a benefit), sounds like a bit of an industry scam to be honest.

Scam? Nooo they wouldn't Scam you. Like charging to change the Air in your tires every oil change.:smiley5:

mitsuguy
02-04-2010, 18:57
there are many many dives that nitrox is just silly for...

for example - our wall dives... average 65 feet for 20 minutes, then 25 feet for 30 - 40 minutes...

If I did a week of those dives - i'd still do them on nitrox. I personally believe nitrox best benefit cannot be felt on a single dive. Its the multi-dive multi-day trips where it really shines.

What if you did it every single day, and sometimes more than twice a day???

I feel no ill side effects, my computer doesn't hate me, and I do at least 15 dives a week...

I believe people feel better on nitrox, sometimes perhaps, because they are not loading as much nitrogen as on air... no empirical data, but it makes a little sense... me, on the other hand, I don't mind / nor does my body, if I do 5 dives in a day, so long as I am staying within my limits...

there is no benefit to me diving nitrox unless there is simply no way to do the planned dives on air...

mmcguire2002
02-05-2010, 10:24
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.

You dive over 100% of the time?

Panmanmatt
02-05-2010, 11:23
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.

You dive over 100% of the time?


Yeah, he dives 100% of the time in the water and the other 5% is spent diving in dreams. Isn't that what everyone does?

ssmdive
02-05-2010, 12:10
Yes!

If I can get Nitrox, I use it. 32% seems to be my favorite. If no Nitrox is available, I get a clean air fill.

As for frequency, it's usually about 75% Nitrox vs. 35% air.

You dive over 100% of the time?


Yeah, he dives 100% of the time in the water and the other 5% is spent diving in dreams. Isn't that what everyone does?


No, you read it wrong. He dives 75% O2 nitrox and thinks normal air is 32% O2. :smiley36:

sterlinghe92
02-05-2010, 19:32
No. If ur diving shallow it doesn't help. 50 to 90 is when nitrox helps the most but it can be used at deeper or lower depths