Nitrox Question

[JKPAO]

Docer , The difference would be the depths you use Nitrox and the depths you would use trimix.
When you take an entry level Nitrox course you do get taught to analize your gas before you leave a station or shop! If you should dive without knowing what gas you are diving well... I know what it could lead too... and if you are using trimix you are past this already sooo!
See you topside! John

 

[ScubaDocER]

Docer , The difference would be the depths you use Nitrox and the depths you would use trimix.
When you take an entry level Nitrox course you do get taught to analize your gas before you leave a station or shop! If you should dive without knowing what gas you are diving well... I know what it could lead too... and if you are using trimix you are past this already sooo!
See you topside! John

I agree John. I wasn't necessarily comparing Trimix and Nitrox. Merely that both should require in water experience before used independent of a certified Instructor. Being taught to analyze your gas in a class room and having to do it at a dive site when you are already multitasking (getting geared up, checking in, making sure you brought your regs with you, checking the batteries in your lights, making sure your dive buddy is ok, etc.) can be 2 different experiences. IMO, an open water dive with Nitrox, and the entire experience of diving with Nitrox should be done with an Instructor before said Instructor hands you a Nitrox card. It's like being given a drivers license without ever being behind the wheel of a car.

 

[tgsmith]

I think you're making a comparison that is quite a stretch........again. Learning to drive a car and learning to dive nitrox in "recreational" limits require entirely different levels of attention, knowledge and active thinking. Entirely.

To get certified in nitrox today, you can even take an online class, then go into a shop for a quick review/hands-on use of an 02 analyzer. Still, I don't hear about hordes of divers dying from OTS, so evidently what the certifying agencies are doing is working, regardless of anyone's opinion.

Frankly, it really isn't as difficult as you're making it sound. I'm almost prompted to think you're trolling, honestly. It really isn't THAT bad. You learn some simple math, theory/risks, learn some tables and that's it. If a diver has trouble with multi-tasking, i.e. using a camera and monitoring depth, duration, and gas pressure then taking a Nitrox course is not going to fix that, nor is it designed/intended to. The task of not exceeding a depth limit is something taught starting in OW.....the purpose is different with nitrox but the task is the same. Diving nitrox does not change this task.

For clarification, SSI(Scuba Schools International) does not require a dive along with their certification......depending. If you want to learn about nitrox and be certified to dive it, then SSI does not require any dives on nitrox before receiving a nitrox c-card.

Now, lets say you're taking your AOW course through SSI. This requires you perform 24 dives total before you can get your AOW card, and 2 dives each for your 4 specialties required for AOW. For instance, a diver may choose wreck, deep, limited-viz/night diving, and navigation. Said diver will need to perform 2 dives for each one of those specialties for them to count towards the AOW specialties fulfillment. So if you did nitrox as one of your 4 specialties towards your SSI AOW certification, then you'll need 2 dives using nitrox for that specialty to count for the AOW certification. Note: An instructor is still not required to be present during these 2 dives.

Either that or the shop I went to for my SSI courses is really jacked up.

Respectfully,

tgsmith

 

[drrich2]

Not true. It depends on what kind of air you are using. I use air in my tanks all the time but can put nitrox in at any time.

If your tank is used for partial pressure blending, you need it to be O2 clean. This is to prevent a fire when pure oxygen is put into the tank. When partial pressure blending, oxygen is put in the tank and air is pumped in on top of it. That same air can be pumped into the tank without putting oxygen into it first. You can use it for air. Air is nitrox. You do need to be careful not to contaminate your O2 clean tank.

If your tank is not used for partial pressure blending, you use can it with regular air fills.

Sorry about the misinformation. Been a bit over 2 years since I got my Nitrox certification; I own a manual, but not sure where it is right now. I don't do any mixing; so far, my Nitrox use has all been EAN 32 on 2 Bonaire shore dive trips, provided by the dive shop.

Richard.

 

[ScubaDocER]

I think you're making a comparison that is quite a stretch........again. Learning to drive a car and learning to dive nitrox in "recreational" limits require entirely different levels of attention, knowledge and active thinking. Entirely.

I would disagree. Both require a great deal of attention. Not doing so can be fatal. The problem is that people are fallible. They drive and dive beyond "recreational" limits if they are not paying attention. Putting a diver in the water with a tank of Nitrox alone for the first time can be as dangerous as putting someone behind the wheel of a car for the first time without any supervision. The ability to pay attention is crucial if one is to survive either situation. While I cannot guarantee that a student will not make a mistake; before I hand them a card with my name on it, I will certainly have dove with them to see how they will respond under duress. Just a personal preference.

It would seem that reality is proving you wrong.

How so? What is the accident analysis on Nitrox divers who have had no in water supervision and drivers who have had no supervision behind the wheel of a car? I am not sure. But until it is answered, reality hasn't proven anything.

To get certified in nitrox today, you can even take an online class, then go into a shop for a quick review/hands-on use of an 02 analyzer. Still, I don't hear about hordes of divers dying from OTS, so evidently what the certifying agencies are doing is working, regardless of anyone's opinion.

I am not sure hordes of people are being certified that way. Just because you can get certified that way, does not mean that you should get certified that way. With the power that Instructors have to certify students when they have succeeded to their expectation, comes the responsibility that Instructors have to ensure that these same students are educated to their best of their ability. If all that an Instructor is going to do is hand out a card after a lecture or two, then I would argue that they are not teaching to the best of their ability. And if they are, and that's the best they can do, then shame on them.

Frankly, it really isn't as difficult as you're making it sound. I'm almost prompted to think you're trolling, honestly.

It don't believe personally that Nitrox is difficult, but I can respect that some people may. In order to ensure that all students are educated about Nitrox, then I appreciate a uniform method of educating them. That would include actually putting them in the water with me, a pair of tanks filled with Nitorx, challenging them in the water to ensure that they have the appropriate attention span to conduct the dives safely, and addressing any questions they may have about actually diving with Nitrox, instead of discussing the theory of Nitrox. Since you have no idea who I am, then I will excuse the trolling comment. You are free to discuss any ideas I have put forth or challenge them in any way you deem appropriate, but to label my statements as trolling is short sighted and narrow minded, honestly.

It really isn't THAT bad. You learn some simple math, theory/risks, learn some tables and that's it.

It's this philosophy of education that is the most dangerous. You assume that students will comprehend information with the same ease that you might. For many people, that's just not so. It's why there are standards that every agency has adopted so that there will be a "bare minimum" of education available to all students. My suggestion or concern would be that all students diving with Nitrox should have at least one dive done with a certified Instructor prior to said Instructor handing them a card. That's it. Feel free to disagree.

If a diver has trouble with multi-tasking, i.e. using a camera and monitoring depth, duration, and gas pressure then taking a Nitrox course is not going to fix that, nor is it designed/intended to.

On this we agree. I do not intend for a Nitrox class to teach people to be responsible divers. I do believe that as an educator it is my responsibility to assist them in understanding the concepts of learning the theory of Nitrox as well as understanding the practical aspects of diving with Nitrox in the water. Just a personal preference.

The task of not exceeding a depth limit is something taught starting in OW.....the purpose is different with nitrox but the task is the same. Diving nitrox does not change this task.

The purpose however becomes even more critical since divers diving with Nitrox have an MOD that they must adhere to. Diving to 115 feet on a 36% mix has different consequences than diving to 115 feet on air.

For clarification, SSI(Scuba Schools International) does not require a dive along with their certification......depending. If you want to learn about nitrox and be certified to dive it, then SSI does not require any dives on nitrox before receiving a nitrox c-card.

While I respect the agency, I have concerns regarding that policy as stated above.

Note: An instructor is still not required to be present during these 2 dives.

I am VERY concerned if an Instructor is not required to be present DURING the dives.
I hope that was simply misstated.

Either that or the shop I went to for my SSI courses is really jacked up.

If the Instructor does not have to be in the water DURING your dives, then I would suggest that the latter is correct.

 

[Diveralan]

Not to get off-topic, but I have to ask. Where does one find these inexpensive nitrox classes? I've been looking and looking, and the best prices I've seen are still around 2/3 the cost of OW or AOW. I mean, my drysuit class, including drysuit rental, was HALF the price of a nitrox class. That's the ONLY reason I don't have a nitrox certification yet.

What does this price include? Does it include one or more dives with an instructor? If it does, is the price of the nitrox fills included?

Let's look at this another way. Let's say you pay $250.00 for a nitrox class ( I personally have never seen one that high). So you plan and pay $2500 for a week long dive trip with 5 days of diving and you make three 60 min dives per day using air. This comes out to $167.00 per dive. Using nitrox you increase your dives to 5 (or more) per day and use nitrox on half your dives. You now have made 10 more dives and spent an extra $430.00 ( class plus 18 nitrox tanks at $10.00 each). Total price of the trip is now $2930.00 or $84.00 per dive.

It gets better for the next trip, All you have to pay for is the nitrox. Go to Bonaire or somewhere else with free or cheep nitrox and it's even a better deal.

Everyone looks at dive trips differently. Personally, I want to dive as much as I possibly can. Nitrox helps me to do this. Once your air consumption is good enough that it does not limit your dives, nitrox is second only to a dive computer in allowing you more time under water. Isn't that what it's all about.

 

[farsidefan1]

Another benefit of Nitrox certainly applies to me but I understand that not all divers experience this advantage. When diving on air I get worn out after about 3 dives a day on a weeklong dive trip. On nitrox I'm feeling fine with 5 dives a day. I believe fitness of the diver has a lot to do with it but as I'm not certain I'll leave the expanation to others with a better understanding of the physiology involved. But it is not a placebo, the effect is signifigant. Firtst time diving with nitros I was amazed at the difference and mentioned it to the divemaster who gave me a "well duh" look and said that seems to be the norm. I'm certaily not in great shape (age 57, 5'11" 225 lbs ) but I swim 1.5 miles 2 or 3 times a week, and mountain bike (when this dam snow stops) so overall condition is reasonable.

 

[Walter]

But it is not a placebo, the effect is signifigant.

Why do you believe the effect of a placebo cannot be significant? To date, there's been one double blind study of this feeling of being less fatigued diving with nitrox. The results indicate it is a placebo. There is room for more study, but until that happens, there's no reason to believe it is anything other than a placebo - the mind is a powerful thing.

 

[lmorin]

ALL Nitrox classes should require dives to go along with the classwork. If you have not dove breathing Nitrox then you should not receive a Nitrox certification card.

Wow! That's a pretty declarative statement. Want to justify it?

My dive computer automatically sets the Nitrox mix level to 21%, otherwise known as "air," and if I'm diving with a different mix, I set my computer to register that percentage. I learned the recommended dive limits for the various standard mixes out of the book. Learned how to measure the mix level in the class, using an oxygen analyzer (but not the one I have encountered most frequently on trips). Learned in the class how to record the necessary info on the tank and in the log book for each dive. Then, I started diving with Nitrox. What, exactly, does the actual underwater part of the dive accomplish for the use of Nitrox that above water tutelage does not?

 

[DaleC]

I have to disagree with you scubadocer; there's no reason to do a dive with an instructor when using nitrox for the first time IMO.

Your points just don't make sense. According to your reasoning a diver would need an instructor along everytime they deviated from their SOP. If you need an instructor to hold your hand so you won't violate a MOD you shouldn't be diving period without a DM much less on nitrox. As far as analysing at the divesite... I don't know anyone who does it recreationally. We analyse at the shop and put a MOD/% sticker on it. Having an instructor go along on the first dive to help one "recheck" it is a bit... much (and assumes one has purchased their own gas analyser. Quite a rarity for someone just doing a nitrox course).

Nitrox is just air with a bit more oxygen added. You can't compare it to Trimix. One is recreational, the other is technical.

There are some important factors that one must learn about its properties and effects and then incorperate into a dive plan true, but all that happens on the surface. Once one descends one should be following the plan made on the surface (which is not a skill covered by the nitrox course). What you are suggesting is that a nitrox instructor is needed to ensure one can follow a simple dive plan. That smacks of remedialism.

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What I like about the nitrox course is that it forces you to think about MOD's, gas physiological effects, OPP's, using tables etc... Information that is important whether one dives nitrox or not. It gets your brain thinking differently (critically) about the gas you're breathing.