nitrox help

[Cazador Submarino]

hey i'm from california where we barely do any nitrox diving. i was looking for some extra down-time, and thought of nitrox. has anyone been through nitrox classes and can tell me a little about what the classes do and about nitrox diving itself?

thanks

[jfjf]

Nitrox removes a little nitrogen from the air and it makes the gas equivalent to breathing air at a depth of approximately 15-20 ft less than your actual depth. If that benefit sounds useful to your diving, then take a class..

[Cazador Submarino]

is it harmful to switch between nitrox and regular enriched scuba air in the same day?

[primalpete]

no

[100days-a-year]

It realistically effects bottom time from about 80' to 120'.Past that you are looking at only marginal gains,but it will probably make you less inclined to get DCS.Shallower than that and boredom sets in for me before I run out of time.
Oxygen is your friend.

[tomt]

Here are some good links:

http://www.gasdiving.co.uk/pages/misc/Nitrox.htm

http://www.trailquest.net/nitrox.html

http://home.att.net/~cmeilahn/NitroxCalculator.html

[Toledo970]

is it harmful to switch between nitrox and regular enriched scuba air in the same day?

What do you mean by "regular enriched scuba air" if not nitrox?

[Cazador Submarino]

i mean the air you get off a normal fill. . .

[Bulit7]

P&D:

Nitrox is very helpfull, like 100days said, when diving 80-100 feet.

Think of it this way: Air has aprox 21% oxigen and aprox 79% Nitrogen. Nitrogen gets held up in your tissues and takes longer to release and is the gas that will give you DCS(decompression sickness) if you ascend before it has a chance to release itself from those tissues. The solution EAN or Nitrox provides is adding Oxigen to regular air and thus reducing the amount of Nitrogen in the gas. Less Nitrogen equals less time spent offgassing. There is a catch: Nitrogen has a MOD. MOD is a Maximum Operating Depth. Due to Oxigen Toxicity, that can cause seizures, one should allways be aware of their MOD and not exceed it or it can be lights out at depth. The no decompression limits with Nitrox are substantially increased when using mixes from 32% O2 to 36% O2. Now days two mixture nitrox computers take all(read most) of the brainwork out of it and have nice features like depth alarms that can be set to remind you that you are reaching a MOD. If this sounds like it is something you can benefit from, take a Nitrox course.

[Teh Wicked]

breathing nitrox anf regular air on the same day is no problems at all. Just gotta make sure that you inform your computer that your switching from dive to dive. Lets say you dive 32% Nitrox at 90fsw. and have 4 bars of nitrogen, now you wait 1.5 hours and just back down to 90fsw on regular air. if you didnt calibrate your computer to act on breathing air you will get bent cause your computer will think all is well but in reality you should only have a bottom time of about 13 minutes.

[Deep Sea Apnea]

P&D:

Nitrox is very helpfull, like 100days said, when diving 80-100 feet.

Think of it this way: Air has aprox 21% oxigen and aprox 79% Nitrogen. Nitrogen gets held up in your tissues and takes longer to release and is the gas that will give you DCS(decompression sickness) if you ascend before it has a chance to release itself from those tissues. The solution EAN or Nitrox provides is adding Oxigen to regular air and thus reducing the amount of Nitrogen in the gas. Less Nitrogen equals less time spent offgassing. There is a catch: Nitrogen has a MOD. MOD is a Maximum Operating Depth. Due to Oxigen Toxicity, that can cause seizures, one should allways be aware of their MOD and not exceed it or it can be lights out at depth. The no decompression limits with Nitrox are substantially increased when using mixes from 32% O2 to 36% O2. Now days two mixture nitrox computers take all(read most) of the brainwork out of it and have nice features like depth alarms that can be set to remind you that you are reaching a MOD. If this sounds like it is something you can benefit from, take a Nitrox course.

I think you and 100days are a bit off. Getting DCS is much more complicated. To many factors, and your mix is not one of them, well not a very big factor at least. I think it is just a false sense of security that you are holding onto. DCS and all other forms of diving related casualties for that matter can happen on air nirorx he02 trimix, you can even get a p.o.i.s. or a.g.e. from a rebreather even a 100% 02 rebreather. Whether air or nitrox, neither is more inclined to get bent. now if you are over weight in poor physical condition unfamiliar with decompression diving and inexperienced, (which will can lead to omitted decompression) those are factors that more likely lead to getting bent, other than having a "bad" day which is more of a reasonable answer to getting bent than the mix you are diving.

[100days-a-year]

Reread my post.Then find some fact based science to contend with any inaccuracy.I'd love to learn about it.

DAN,NEDU,Duke university and numerous commercial dive interests make the same claims hence their use of nitrox mixtures whenever possible.

Not that "undeserved" hits won't occur but why else would they be called "undeserved"?

[Bulit7]

I think you and 100days are a bit off. Getting DCS is much more complicated. To many factors, and your mix is not one of them, well not a very big factor at least. I think it is just a false sense of security that you are holding onto. DCS and all other forms of diving related casualties for that matter can happen on air nirorx he02 trimix, you can even get a p.o.i.s. or a.g.e. from a rebreather even a 100% 02 rebreather. Whether air or nitrox, neither is more inclined to get bent. now if you are over weight in poor physical condition unfamiliar with decompression diving and inexperienced, (which will can lead to omitted decompression) those are factors that more likely lead to getting bent, other than having a "bad" day which is more of a reasonable answer to getting bent than the mix you are diving.


If you are diving the same exact profile with air and with Nitrox, you are absorbing less Nitrogen. Less Nitrogen equals less tissue loading and longer no deco times. Is that not safer?

Any diving has inherent risks whether air or EAN. I think a lot of people on here know a lot more than you are giving them credit for.

[dirtbroker]

For an add bit of conservitism, you can breathe nitrox, while leaving your computer, set to the air tables

[No Misses]

For an add bit of conservitism, you can breathe nitrox, while leaving your computer, set to the air tables

I do not want to be a troll.

What you suggest is very dangerous. Here is one example. You are diving EAN 36 - you leave your computer set for air - You drop in on a gradual ledge and start following a fish that is going deeper. Your dive computer will be happy with you until you max your nitrogen or decend past it's "max depth" setting (depends on programming and on computer. we will say it is 130 fsw in this example) - once you get to 114 fsw you have reached the MOD of EAN 36. If you follow that fish down any further you are at risk of taking an O2 hit (Oxygen Toxicity). The moral of the story is DO NOT LIE TO YOUR DC. If you want to dive conservative use your brain or buy a DC that has programmable consevatism settings.

End of rant :-)

P.S. I dive EANx on almost every dive.

[100days-a-year]

No Misses,anyone that stupid shouldn't be diving anyway.The 6 Ps were taught to me as a kid and reiterated in every class I've taken.
ie:Proper Planning Prevents Piss Poor Performance

It is common for actual nitrox divers to be capable enough to know their MOD and not exceed it.

I dive nitrox on an old air computer because modern computers are designed by chicken little and his staff of fellow hand wringers.
They are far to conservative on repetitive diving after giving you tons of extra time on the first dive.I can recall dives in 140' where VPM and my air computer cleared and my supposedly "liberal"Oceanic or Aeris nitrox computers had me hanging for almost a half hour more when dove side by side 3-5 dives in one day.

[Bulit7]

I do not want to be a troll.

What you suggest is very dangerous. Here is one example. You are diving EAN 36 - you leave your computer set for air - You drop in on a gradual ledge and start following a fish that is going deeper. Your dive computer will be happy with you until you max your nitrogen or decend past it's "max depth" setting (depends on programming and on computer. we will say it is 130 fsw in this example) - once you get to 114 fsw you have reached the MOD of EAN 36. If you follow that fish down any further you are at risk of taking an O2 hit (Oxygen Toxicity). The moral of the story is DO NOT LIE TO YOUR DC. If you want to dive conservative use your brain or buy a DC that has programmable consevatism settings.

End of rant :-)

P.S. I dive EANx on almost every dive.

Your post is not a Troll post. You make a great point that cannot be said enough. If you are going to use Nitrox, learn how to use it, keep that info fresh in your mind, DIVE OFTEN. It does you no good to dive once or twice a year.

[BobK]

No Misses,anyone that stupid shouldn't be diving anyway.The 6 Ps were taught to me as a kid and reiterated in every class I've taken.
ie:Proper Planning Prevents Piss Poor Performance

It is common for actual nitrox divers to be capable enough to know their MOD and not exceed it.

I dive nitrox on an old air computer because modern computers are designed by chicken little and his staff of fellow hand wringers.
They are far to conservative on repetitive diving after giving you tons of extra time on the first dive.I can recall dives in 140' where VPM and my air computer cleared and my supposedly "liberal"Oceanic or Aeris nitrox computers had me hanging for almost a half hour more when dove side by side 3-5 dives in one day.

With all due respect, if you're going to dive using your dive computer, listen to it. If you're going to dive by screwing around and lying to it, what the hell are you doing using that dive computer ? If you want more liberal time, change your computer or dive tables. If you want to dive NITROX and pretend you're diving air, use a table. It is a poor idea to tell others here that they should start "cheating" on computers. Many don't understand the issues, and you are simply going to get someone bent or hurt. It's been a tough enough year.

[lgsliptip]

take the class and remeber what you have are told this is the way of the sea.

[Teh Wicked]

I dunno if anyone else feels the way I do, But after a day of diving on Nitrox I feel WAY better than a day of diving on air. Now when I dive I dive nothing but nitrox, weather it be in 25fsw at my favorite snapper hole near the skyway bridge, or diving to 130fsw at the Middle Grounds 100 miles off shore.

[Bulit7]

With all due respect, if you're going to dive using your dive computer, listen to it. If you're going to dive by screwing around and lying to it, what the hell are you doing using that dive computer ? If you want more liberal time, change your computer or dive tables. If you want to dive NITROX and pretend you're diving air, use a table. It is a poor idea to tell others here that they should start "cheating" on computers. Many don't understand the issues, and you are simply going to get someone bent or hurt. It's been a tough enough year.

Diving Nitrox with an air computer is perfectly fine and even recomended. What is wrong with that?

take the class and remeber what you have are told this is the way of the sea.

LOL! WTF! That last shot of Jack should have never left the bottle!:D

I dunno if anyone else feels the way I do, But after a day of diving on Nitrox I feel WAY better than a day of diving on air. Now when I dive I dive nothing but nitrox, weather it be in 25fsw at my favorite snapper hole near the skyway bridge, or diving to 130fsw at the Middle Grounds 100 miles off shore.


It is interesting that you mention this. I have had the same experience.
Oxigen is a healing gas. It is great for your cells and brain if used correctly.

I have asthma(mild) or RAD(Reactive Airway Disease) from all the chemicals and paint inhaled over the years. I used to have to use Albutherol almost daily and spent a week in the hospital due to a shortness of breath. Then I started diving NITROX a lot, almost twice a week and it cured me. I rarely get short of breath anymore. When I dive NITROX I also feel really well. That is some amazing shit.:thumps:

[Mike Edmonston]

Facts:

1. Nitrox allows you to dive longer than air.
2. Nitrox can shorten your surface interval between dives.
3. Nitrox diving is DEPTH LIMITED due to Oxygen Partial pressures.
4. Since some Nitrogen is being removed from the final mix, there is less ongassing, therefore you reduce (not eliminate) your chance of a DCS hit.
5. Diving Nitrox using AIR TABLES, will again reduce your chance of a DCS hit, as you are adding extra conservatism. This DOES NOT APPLY to dive computers! Alot of divers don't have the forethought to monitor their SPG, let alone their Po2 and MOD while they are stepping on a reef, or noodeling for moray eels! read: BAD IDEA!!!
6. In some pople, diving Nitrox will make you feel better and less tired after a dive. I personally feel this way, other divers may not.
7. Oxygen is treated with the same narcotic potential as Nitrogen, therefore Narcosis effects are not reduced. (This is the agency position on this, I have my own position in regards to O2 and Narcosis, but that is for another time)

So that's it in a nutshell. Take a class, learn to analyze your mix, and get familiar with figuring out your best mix for depth, and not exceeding your MOD.

After all, it's the Devil's gas!!!! ;)

Safe Diving

[jfjf]

Facts:
5. Diving Nitrox using AIR TABLES, will again reduce your chance of a DCS hit, as you are adding extra conservatism. This DOES NOT APPLY to dive computers!

I disagree with this statement, so I assume that I misunderstand your comments. It seems that using an air computer and diving nitrox should be analogous to using an air table and diving nitrox; at least with respect to DCS?

[Mike Edmonston]

I disagree with this statement, so I assume that I misunderstand your comments. It seems that using an air computer and diving nitrox should be analogous to using an air table and diving nitrox; at least with respect to DCS?

Calculations are the same. Situational awareness of the diver in respect to not exceeding MOD is not.

Air computers will not tell you when your Po2 is above setpoint (1.6 for OC divers)

You tox = You drown.

Safe Diving

[100days-a-year]

MikeE,you mentioned that divers situational awareness not being sufficient to monitor guages while diving.That also applies to computers.Telling it you are on nitrox and not looking at it is the same as lieing to it.Once again I reiterate that clowns who are unaware of the dangers and unable to do the math themselves are still clueless with a computer.And shouldn't be underwater spearfishing anyway.

I started diving nitrox before there was a class,computer or retail source for it by reading the available literature and listening to guys doing it.I only took the class a maybe 15 years ago as it was going to be required as a pre-req for my trimix class.
I use the configuration I do because it works and gets me out of the water unbent in thousands of dives and quicker than a nitrox computer at any depth over 120' In fact the only nitrox computer that is similar in times are the Cochrans and too many friends have had them sh&t out on the boat.

[BobK]

MikeE,you mentioned that divers situational awareness not being sufficient to monitor guages while diving.That also applies to computers.Telling it you are on nitrox and not looking at it is the same as lieing to it.

That's simplistic and not the issue. What is really going to happen is that people are going to think it's great to dive a NITROX mix and use an air computer to do it. Isn't this what you do ? And then what happens is, near the end of the dive, they'll see the fish of a lifetime. Their brain says, "Hey, I'm really diving NITROX, I have extra time !". They go get the fish. I don't know you but I would bet good money you've done this. So, after a few times of doing this, perhaps even over a period of years, it becomes a habit. But the diver no longer has a good handle on where they are in relation to their NDL limits, and the potential to get bent goes up.

I believe this because something similar is already happening with pony tanks. Pony tanks were designed to be an EMERGENCY backup to backgas because the diver was solo diving (Disclaimer: I solo all the time, like most of you). But with certain divers, the pony tank has become a gas extender. I have picked up divers having an in water emergency because they exhausted their back gas and then their pony because they were chasing a nice fish. They had totally lost the concept of what that pony gas was for. Same thing diving NITROX but using an air computer. Eventually people are going to (And I'm sure currently do) forget the original reason and start extending their BT time arbitrarily. And then the trouble will begin.

If you want the extra time from a NITROX mix, dive with a NITROX table or computer. At the end of your BT, you'll know you're at the end, or you need to do deco. Otherwise you're just guessing. Guessing in diving gets people in trouble.

[100days-a-year]

And exactly what will keep the same clowns from exceeding the MOD of their mix just because they have computer on?A flashing icon they are not looking at?An inaudible beep that can only be heard in the diveshop?

Explain very simply what mechanism in a computer keeps the same guy who would chase past his MOD after a fish with an air computer will be prevented from doing so by this nitrox computer.

Not trying be a jerk,I know you guys mean well but I dive a lot with a lot of different people and I prefer those who know exactly what their capabilities are in any given situation to those who are only safe within a narrow window of Utopian scenarios.

[Bulit7]

That's simplistic and not the issue. What is really going to happen is that people are going to think it's great to dive a NITROX mix and use an air computer to do it. Isn't this what you do ? And then what happens is, near the end of the dive, they'll see the fish of a lifetime. Their brain says, "Hey, I'm really diving NITROX, I have extra time !". They go get the fish. I don't know you but I would bet good money you've done this. So, after a few times of doing this, perhaps even over a period of years, it becomes a habit. But the diver no longer has a good handle on where they are in relation to their NDL limits, and the potential to get bent goes up.

I believe this because something similar is already happening with pony tanks. Pony tanks were designed to be an EMERGENCY backup to backgas because the diver was solo diving (Disclaimer: I solo all the time, like most of you). But with certain divers, the pony tank has become a gas extender. I have picked up divers having an in water emergency because they exhausted their back gas and then their pony because they were chasing a nice fish. They had totally lost the concept of what that pony gas was for. Same thing diving NITROX but using an air computer. Eventually people are going to (And I'm sure currently do) forget the original reason and start extending their BT time arbitrarily. And then the trouble will begin.

If you want the extra time from a NITROX mix, dive with a NITROX table or computer. At the end of your BT, you'll know you're at the end, or you need to do deco. Otherwise you're just guessing. Guessing in diving gets people in trouble.

I think that is a generalization and does not apply to all scenarios and divers.

Some people will push the limits and incorporate unsafe practices into their profiles. I have seen it done. Others will be conservative and cautious. Yet others will find a middle line between safety and all out madness. In the end I think that the danger is not in the fact that a diver uses an air computer to dive Nitrox but how safe and knowledgable the diver is with regards to his equipment, technique and knowledge of his own limitations. All things being equal, a guy that dives conservatively and uses an air computer with Nitrox is less likely to get an undeserved hit. From my point of view this is a no brainer.

Now take a diver that pushes the limits and that is a diver that will do so regardless of what equipment he is using. Same goes for someone that does not have a solid understanding of Nitrox use and limitations or someone that dives once a year and is not fluent due to lack of practice. I am pretty sure that is one analizes fatalities, those two factors will be the predominant determinators of diver fatality.

I for one dove a Nitrox computer for a while that a friend let me borrow. When I returned it to him I was without one for a while and dove my air console. Never did I exceed my computer or blow off deco. I did short decos a few times with it knowing perfectly well that I did not need to because it was a profile that I had done hundreds of times. Then again, never did I use my pony, never did I use my pony to continue diving and never did I surface from 80 feet plus with less than 300-700psi in my tank. That is just me.

[jfjf]

Calculations are the same. Situational awareness of the diver in respect to not exceeding MOD is not.

Air computers will not tell you when your Po2 is above setpoint (1.6 for OC divers)

You tox = You drown.

Safe Diving

Well I tried.... You tell us that using air tables with nitrox is OK, but a computer who thinks your are breathing air is going to facilitate an exceedance of the MOD for nitrox. Exactly how do the air tables prevent this?

[Bulit7]

Well I tried.... You tell us that using air tables with nitrox is OK, but a computer who thinks your are breathing air is going to facilitate an exceedance of the MOD for nitrox. Exactly how do the air tables prevent this?

I think that because when you plan your dive using a table, you specificly plan your max depth and adhere to it. When diving a computer, it does all your depth/saturation calculations automaticly and you may forget the gases MOD due to this fact.

I don't know about you guys but I love these tech threads cause even though I havent been diving in over a month, they keep my brain fresh on the principles and you allways learn something new.

[100days-a-year]

:lol:Hah,I'm going out Wed or Thursday for a week hopefully.

Just hope the 11' swells don't FUBAR the vis.I haven't dove in a few weeks myself due to nor'easters and a family adrenaline vacation obligation.

[Bulit7]

LOL! I know...I'm pathetic! What can I say, I worked Saturday and Sunday till 6pm both days. Took today off.
I need to get out.

[Grin]

Internet information is great for getting ideas about what you are looking to try to accomplish, but everyone looks at the situation from their personal experience. For all we know this guy may be planning to do 5 tanks tomorrow. So he reads all the experts here and fills up with 40 Nitrox for 5 tanks and dives his air computer to be conservative. On the 4 th tank he starts his dive at 110% daily oxygen limit and has no clue.
I tend to agree with the crowd that says trying to add conservatism into your dive by outsmarting your computer is not a good idea. If you know everything and are experienced, then it might not be to bad to do it with the knowledge of the limits your not able to watch accuratly by not using proper equipment. But what's the point! Using your computer to outsmart you is not the greatest idea I've heard. You get so concerned about taking a Nitrogen related hit noone mentioned the daily O2 limit that kills.

[Mike Edmonston]

A couple thoughts,

If you're going to dive Nitrox, don't bother with an air computer. Just plan your dive on tables. At recreational depths, you will have plenty of bottom time. If you want to be extra conservative, then plan using air tables. The main thing to remember is your MOD. Exceeding this could cause you to have a CNS toxicity hit. These Hits have a nasty habit of killing the diver by drowning, as the seizure makes them bite through the mouthpiece, and lose the reg. Pulmonary toxicity is caused by long term exposure to higher levels of Po2 over a period of time. Although you will feel out of breath, and your lungs will be irritated, it will not generally kill you.

Tracking both your CNS and your OTU's for Po2 exposure is important to minimize toxicity issues.

Safe diving all,

[Mike Edmonston]

:lol:Hah,I'm going out Wed or Thursday for a week hopefully.

Just hope the 11' swells don't FUBAR the vis.I haven't dove in a few weeks myself due to nor'easters and a family adrenaline vacation obligation.

I hope your cooler's so full of fish that you can't lift it off the boat!

Have fun and safe diving. :D

[100days-a-year]

Thanx,waiting for the word and I am on it.Hope to look at some new stuff too.Got about 1000 new # recently,some say wreck and I didn't have them already.Love to see new.

[BobK]

And exactly what will keep the same clowns from exceeding the MOD of their mix just because they have computer on?A flashing icon they are not looking at?An inaudible beep that can only be heard in the diveshop?

Nothing. I dove with someone one time who was diving air, I was diving something like 34 %. They stayed with me the whole dive, but kept checking their computer. When we surfaced, turns out their computer wanted them to do a 7 minute deco for the dive. Since they had just bought the computer, and apparently didn't understand what it was telling them, they just stuck around with me. :eek:

I don't think divers like this are rare. You obviously aren't in this category, but passing on knowledge you have picked up over the years in a few abbreviated paragraphs on the internet could lead someone like my "friend" to do something stupid without understanding what or why.


Explain very simply what mechanism in a computer keeps the same guy who would chase past his MOD after a fish with an air computer will be prevented from doing so by this nitrox computer.


Again, nothing. But at least when he sees his NDL is done with the NITROX computer he couldn't pretend he "really has more NDL bottom time". With an air computer he could decide he does have more NDL time. The problem is, how much more ? I've noticed that spearfishers tend to be optimistic...


Not trying be a jerk,I know you guys mean well but I dive a lot with a lot of different people and I prefer those who know exactly what their capabilities are in any given situation to those who are only safe within a narrow window of Utopian scenarios.

No doubt. I'm not talking about you or your experienced friends. I'm talking about those who read this stuff and believe it. We need to be careful what we pass out as good ideas, because often times the details don't get conveyed. Like pulling the pin on a grenade and counting to 3 before throwing it, so it will go off as soon as it hits the ground near the enemy. Good idea in some scenarios. But one of the details that may not get passed along is that in this case using a grenade with a 3 second fuse may be a bad idea :(

[Cazador Submarino]

Internet information is great for getting ideas about what you are looking to try to accomplish, but everyone looks at the situation from their personal experience. For all we know this guy may be planning to do 5 tanks tomorrow. So he reads all the experts here and fills up with 40 Nitrox for 5 tanks and dives his air computer to be conservative. On the 4 th tank he starts his dive at 110% daily oxygen limit and has no clue.
I tend to agree with the crowd that says trying to add conservatism into your dive by outsmarting your computer is not a good idea. If you know everything and are experienced, then it might not be to bad to do it with the knowledge of the limits your not able to watch accuratly by not using proper equipment. But what's the point! Using your computer to outsmart you is not the greatest idea I've heard. You get so concerned about taking a Nitrogen related hit noone mentioned the daily O2 limit that kills.

I'll tell you guys my exact thoughts. I was at my local dive shop and my dad pointed out some steel 130's and we're seriously thinking of buying one for each of us. we were thinking about taking them and an aluminum 80 each out on a dive trips to our outer channel islands where we usually dive 4 dives a day. we would get a nitrox fill on the two 130's and use those on our first dive, usually the deepest at about 90-100 MD. then, we would use the 130's wih normal SCUBA air for the next dive, and use our aluminum 80's for the last two, and the shallowest dives.

[keyshunter25]

Please please please don't base your decision on whether to go to Nitrox on what people have to say about it online. Some of this information is good and some of it will kill you. Go talk to a Dive Instructor that you trust and you believe knows what he is talking about and let them explain it to you. Or do some research online from reliable sources, not just random divers. I respect all your opinions, but it's your life!

[Bulit7]

I'll tell you guys my exact thoughts. I was at my local dive shop and my dad pointed out some steel 130's and we're seriously thinking of buying one for each of us. we were thinking about taking them and an aluminum 80 each out on a dive trips to our outer channel islands where we usually dive 4 dives a day. we would get a nitrox fill on the two 130's and use those on our first dive, usually the deepest at about 90-100 MD. then, we would use the 130's wih normal SCUBA air for the next dive, and use our aluminum 80's for the last two, and the shallowest dives.


Makes more sense to dive Nitrox all the way around. Less off gassing is better. The only time I use air is when diving very deep, 140-160(on occasion) I or when diving shallower than 40 (very rare). Moist of my drops are in the 80-140 range.

[Cazador Submarino]

Makes more sense to dive Nitrox all the way around. Less off gassing is better. The only time I use air is when diving very deep, 140-160(on occasion) I or when diving shallower than 40 (very rare). Moist of my drops are in the 80-140 range.

kind of a noob question, but how don't you get narced at 140?

[Mike Edmonston]

kind of a noob question, but how don't you get narced at 140?

Narcosis starts affecting people at 100' or so. Although alot of people don't "feel" the effects until deeper. It is a very subjective effect.

Any deeper than recreational depths (130'), and a Hyperoxic recreational trimix gas will minimize the narcosis, while allowing you to spear at deeper depths.

Safe Diving

[Grin]

NITROX is great and very safe. But you still need to know the basics to be safe. Simply take the class and be happy.
I would want tanks that are close to the same bouyancy to make my diving learning curve a little easier. One steel tank and one Aluminum tank will require major weight change calculations between dives. A smart thing to do would be to have each diver have his same kind of tanks. I'd get two steel 120s or 130s for each diver. you'll be glad you did. If not that, two AL 80s would be better than the mix match set.

[Cazador Submarino]

yeah man you bring up a good point

[islanduni]

I have done it both ways 21% to NITROX thru the day and NITROX all day or 21!% all day.

If you mix gases leave NITROX for the last dives of the day to stay clean.

If you dive 21% have 100% O2 to hang off on.

The danger with NITROX is getting bent, it can kill you!

In California at the islands it is the best choice.

Jim

[jadairiii]

...The danger with NITROX is getting bent, it can kill you!
Jim


Never mind that this thread is close to a year old. The above quote seems a tad odd.

Nitrox is Air, getting bent on Air, Nitrox, Trimix, or Heliox can kill you. There is no greater danger to Nitrox than any of the other mixes.

If your Nitrox instructor taught you that quote, go get your money back.

John