Is nitrox worth it for deeper rec dives?

[Jack Hammer]

@Marie13, most folks I know locally dive Nitrox at the depths you've asked about. It gives you much better conservatism and most people I've spoken with, myself included, feel better after dives with Nitrox. DRIS banks 32%. Any mix under that can be done with a combo of 32% and air. To the best of my knowlege you shouldn't need O2 cleaning for that.
If you're uncertain if Nitrox is worth the additional cost to you, perhaps try it for a few dives and see if you find the cost to benefit ratio justifiable. I do.

 

[KenGordon]

We saved a bit of money by only having the 'Nitrox' fill for the afternoon, then cheated by adding air for the second.

Marie, do this - assuming your second dive is less than 33m. Get your cylinders o2 cleaned, then get a first fill of 28, a second fill of 32 then the next is an air top to 25 or 26, then next 32 then an air top etc. So only half your fills are expensive.

Your issue here illustrates a problem with having a big gap between NDL diving and full up accelerated deco, carrying a rich mix. The dives you are describing are medium experienced sports diver territory (strictly a 35m limit) where backgas deco is fine.

You could have a 20 or 25 minute bottom time, instead of something like 8.

You are calling these rec dives by some narrow definition involv8ng depth and deco. Really though a 40m twinset, cold water, wreck dive is a proper dive and due consideration is required in planning, execution and choice of buddy. You only need to get delayed by a couple of minutes by some issue and you will be into a reasonable length deco.

 

[Zef]

Her first post states that DRIS banks 32%

Thanks for pointing this out, I had not considered that, but even with that info it could very well be that DRIS will not fill a tank with enriched air regardless of %O2 unless it is O2 cleaned...I don't know if that is the case but that seems to be the impression that I have gleaned from what Marie13 has posted. If it is not the case and DRIS will fill a non-O2 cleaned cylinder with banked enriched air then it is up to Marie13 to engage with them to sort this out. We can only encourage her to do this but in the end the onus is on her....She is an intelligent woman, she will either use the info presented in this thread to help her engage DRIS on the subject of the fill or not, as well as solidify her decision on whether it is a good idea for her to use EANx at all and/or have her tanks O2 cleaned. There is a lot of good information being passed here on the subject for one to think about that has made the creation of this thread worthwhile.

-Z

 

[guruboy]

Thanks for pointing this out, I had not considered that, but even with that info it could very well be that DRIS will not fill a tank with enriched air regardless of %O2 unless it is O2 cleaned...I don't know if that is the case but that seems to be the impression that I have gleaned from what Marie13 has posted. If it is not the case and DRIS will fill a non-O2 cleaned cylinder with banked enriched air then it is up to Marie13 to engage with them to sort this out. We can only encourage her to do this but in the end the onus is on her....She is an intelligent woman, she will either use the info presented in this thread to help her engage DRIS on the subject of the fill or not, as well as solidify her decision on whether it is a good idea for her to use EANx at all and/or have her tanks O2 cleaned. There is a lot of good information being passed here on the subject for one to think about that has made the creation of this thread worthwhile.

-Z

If you read the thread, you would understand that the issue is not DRIS but that the places she goes to dive will likely provide partial pressure blending only. That is why she would need O2 cleaning.

 

[Zef]

If you read the thread, you would understand that the issue is not DRIS but that the places she goes to dive will likely provide partial pressure blending only. That is why she would need O2 cleaning.

That is what I gleaned as well. Hence why I don't understand the curt and unhelpful remarks about her painting herself into a corner. She dives in a corner of the world that has limited resources available to divers. She is trying to figure out the best way to manage the available resources, her budget, and possibly a myriad of any other factors.

I have no idea how much diving she has under her belt but based on the fact that my wife bought her drysuit from her that Marie13 purchased new in 2016, she has at least 2 years of diving in the cold, low-viz environment of the great lakes and local quarries in Illinois/Wiscosin, and she dives relatively year round for as much as the dive centers she dives with operate through the winter months. To me that is commendable and inspiring. I would take her 2+ years of diving and put it against 10 years of someone diving in the warm, clear tropics any day.

There was a comment that she has a general lack of experience (post #31)...I think the person who wrote that should re-evaluate that sentiment because while her experience may be somewhat limited it is definitely not lacking.

We all have more to learn, every one of us.

-Z

 

[guruboy]

That is what I gleaned as well. Hence why I don't understand the curt and unhelpful remarks about her painting herself into a corner. She dives in a corner of the world that has limited resources available to divers. She is trying to figure out the best way to manage the available resources, her budget, and possibly a myriad of any other factors.

I have no idea how much diving she has under her belt but based on the fact that my wife bought her drysuit from her that Marie13 purchased new in 2016, she has at least 2 years of diving in the cold, low-viz environment of the great lakes and local quarries in Illinois/Wiscosin, and she dives relatively year round for as much as the dive centers she dives with operate through the winter months. To me that is commendable and inspiring. I would take her 2+ years of diving and put it against 10 years of someone diving in the warm, clear tropics any day.

There was a comment that she has a general lack of experience (post #31)...I think the person who wrote that should re-evaluate that sentiment because while her experience may be somewhat limited it is definitely not lacking.

We all have more to learn, every one of us.

-Z

People get annoyed because she will often start a thread “asking” a question but then ignores any “advice” that disagrees with what she already thinks.

 

[Zef]

People get annoyed because she will often start a thread “asking” a question but then ignores any “advice” that disagrees with what she already thinks.

People who get annoyed by that should stay off internet forums.

Giving advice is like giving someone a an arrow to put in a quiver or a tool in a toolbox...the receiver is not obligated to employ it immediately or ever, but having it enhances their ability as should they decide to employ it they have the right tool. If the person who gives the advice has any expectation for what the receiver does with it after it is given they may certainly find themselves annoyed/frustrated. If the advice is given without any expectation then there is far less chance for annoyance/frustration all around.

I have 2 teenagers in my house. I learned a long time ago that my role as parent is to guide and advise them on most subjects not dictate their course of action. There are obviously somethings that are indeed dictated but for most things the ultimate decision is up to them. I can impart good study techniques but it is up to them to employ them. I can suggest how to handle a situation with a teacher or a friend but it is up to them ultimately to make the choice of how they will handle things. In my military career (prior enlisted and retired US Naval Officer) and as a parent I have learned that good leadership and parenting often involves letting people make mistakes and being there to help them when they hit bottom; help them up, dust them off, and get them ready for the next round of life. Is it frustrating to watch my kids fail or suffer at their own hand? sure. Is it frustrating when they ask me the same question after the fact that I already answered before the fact? sure. Do I thank god that they continue to engage me even though they know full well they sometimes ignore the advice? You bet your arse I do! Remember, the butterfly has to squeeze itself out of its own cocoon before its wings can take flight.

It can be painful and frustrating to watch sometimes but it is more painful, frustrating, and damaging to go through life annoyed that your advice/help is not being taken advantage of the way you think it ought to be.

Just my .02 cents

-Z

 

[Mike1967]

Just my .02 cents

More like $2.02

 

[Ryan Mcshane]

Are the depths stated to the seabed or on the actual parts of the wrecks you’ll be diving? We’ve got a lot of wrecks in Scapa Flow that are 130ft to the seabed but the majority of stuff you’re there to see is 90-100ft. People end up asking for whacky mixes when you can do the majority on 32%

 

[rongoodman]

Your dives were deco dives, from the looks of it. Mine are not (not for a couple more years, at least).

A couple of days spent doing AN/DP/Helitrox would render most of this discussion moot. It isn't rocket surgery, after all. As someone above said, more tools in the toolbox. I've done enough dives up here in similar conditions to know that if I was still interested in doing them I'd be using a light mix whenever I could, so I could remember more of what I saw when back on the boat.