Air strategy for 4-5 tank dive days?

[Efka76]

1) The NDL may be incorrect but you cannot deny that it is a more conservative NDL as compared to setting the computer to diving EAN32.
2) @Diver0001 also provided the context that his buddy did not dive deeper than 100ft which demonstrates that his buddy has a dive plan, and he sticks to his dive plan. When diving EANx, is it not a policy to check your depth as you're diving to make sure you're staying within limits? Your critique make it seems as if people are solely dependent on the MOD alarm to highlight the fact that there are near MOD.

1) Yes, NDL will be more conservative. This is pretty clear.
2) When you diving Nitrox you have to check you depth. If you exceed it oxygen becomes toxic and you can drown due to this. If you read at least few accident reports you would note that there is always the same pattern which leads to big issues or fatalities. In this case person will set up his computer on "Air" and might simply forget that he is diving nitrox, might see turtle, shark and will go deeper.... and he is dead.

I read about accidents when very experienced technical instructors died because they made small mistakes. Here, in this case, setting computer on "Air" when diving Nitrox is a very big mistake. MOD alarm is a very good preventive control which informs you when you reach your limit. I would suggest you to take Nitrox course or revise your knowledge in order to better understand what are risks involved Nitrox diving.

 

[Strategist.]

1) Yes, NDL will be more conservative. This is pretty clear.
2) When you diving Nitrox you have to check you depth. If you exceed it oxygen becomes toxic and you can drown due to this. If you read at least few accident reports you would note that there is always the same pattern which leads to big issues or fatalities. In this case person will set up his computer on "Air" and might simply forget that he is diving nitrox, might see turtle, shark and will go deeper.... and he is dead.

I read about accidents when very experienced technical instructors died because they made small mistakes. Here, in this case, setting computer on "Air" when diving Nitrox is a very big mistake. MOD alarm is a very good preventive control which informs you when you reach your limit. I would suggest you to take Nitrox course or revise your knowledge in order to better understand what are risks involved Nitrox diving.

1) Good, then we are clear that it is a more conservative NDL and thus does not present the risks that you've mentioned in your earlier post.
2) Please refer back to my post when I said his buddy plans his dive, and dives his plan. I also made clear with a rhetorical question, "is it not a policy to check your depth as you're diving...?" If you struggle with reading rhetorics, please take some time to digest what people are saying before replying for the sake for doing so. While I do not advocate for his style of diving, it is a risk he undertakes and an additional task load of constantly checking his depth. Therefore, I agree with the possibility that it is indeed possible for him to go deeper than the MOD and possibly suffer from OxTox.

I disagree, however, that setting Air while diving Nitrox is a "very big mistake". I think it has its benefits given that the user understands the risks behind it. Does it increase conservative NDLs? Yes, at the expense of task loading. Is it worth it? Not for me. I prefer not to be task loaded.

Please be clear on what I am arguing for, instead of asserting your position on my point vicariously without understanding my intent. Part of diving EANx is to check the FO2 and write the MOD before every dive. Thus, that implies that regardless of diving Air/EANx on the computer, the user has to check the depth consistently. While @Diver0001's buddy undertakes the risks of not relying on the PO2 on his computer in exchange for more conservative NDL, it is simply not my "dive style" to do that. What I am doing, and perhaps what you fail to understand is that I am seeing the rationality behind the actions of diving that way and the possible risks that he undertakes.

Additionally, please do not assert your assumptions on my knowledge on EANx before you understand my stance and my purpose.

 

[Efka76]

1) Good, then we are clear that it is a more conservative NDL and thus does not present the risks that you've mentioned in your earlier post.
2) Please refer back to my post when I said his buddy plans his dive, and dives his plan. I also made clear with a rhetorical question, "is it not a policy to check your depth as you're diving...?" If you struggle with reading rhetorics, please take some time to digest what people are saying before replying for the sake for doing so. While I do not advocate for his style of diving, it is a risk he undertakes and an additional task load of constantly checking his depth. Therefore, I agree with the possibility that it is indeed possible for him to go deeper than the MOD and possibly suffer from OxTox.

I disagree, however, that setting Air while diving Nitrox is a "very big mistake". I think it has its benefits given that the user understands the risks behind it. Does it increase conservative NDLs? Yes, at the expense of task loading. Is it worth it? Not for me. I prefer not to be task loaded.

Please be clear on what I am arguing for, instead of asserting your position on my point vicariously without understanding my intent. Part of diving EANx is to check the FO2 and write the MOD before every dive. Thus, that implies that regardless of diving Air/EANx on the computer, the user has to check the depth consistently. While @Diver0001's buddy undertakes the risks of not relying on the PO2 on his computer in exchange for more conservative NDL, it is simply not my "dive style" to do that. What I am doing, and perhaps what you fail to understand is that I am seeing the rationality behind the actions of diving that way and the possible risks that he undertakes.

Additionally, please do not assert your assumptions on my knowledge on EANx before you understand my stance and my purpose.

It seems that we live in different worlds. I still think that IT IS A BIG MISTAKE TO SET DIVING COMPUTER ON AIR WHEN DIVING NITROX. In this case diver adds unnecessary additionally risks and task loading. By reading your comments I still have opinion that you need to read or re-read materials on Nitrox diving as you still do not have understanding of risks involved. Also, I do not know and do not care how many dives you have under your belt but I would never dive with such buddy as you.

 

[Strategist.]

It seems that we live in different worlds. I still think that IT IS A BIG MISTAKE TO SET DIVING COMPUTER ON AIR WHEN DIVING NITROX. In this case diver adds unnecessary additionally risks and task loading. By reading your comments I still have opinion that you need to read or re-read materials on Nitrox diving as you still do not have understanding of risks involved. Also, I do not know and do not care how many dives you have under your belt but I would never dive with such buddy as you.

I wouldn't dive with someone who would resort to ad hominem attacks or someone who isn't capable of replying in a civil manner as well. I'm glad that our opinions are alike for this matter.

 

[ChuckP]

It seems that we live in different worlds. I still think that IT IS A BIG MISTAKE TO SET DIVING COMPUTER ON AIR WHEN DIVING NITROX. In this case diver adds unnecessary additionally risks and task loading. By reading your comments I still have opinion that you need to read or re-read materials on Nitrox diving as you still do not have understanding of risks involved. Also, I do not know and do not care how many dives you have under your belt but I would never dive with such buddy as you.

One of the points in the nitrox class was to dive nitrox using air tables - added safety margin.

If you are not confident in your depth control or your awareness, you probably shouldn’t be diving that close to the MOD anyways.

Are you aware that people decompress at a ppo of 1.6? No working situations but there is margin there.

 

[Efka76]

One of the points in the nitrox class was to dive nitrox using air tables - added safety margin.

If you are not confident in your depth control or your awareness, you probably shouldn’t be diving that close to the MOD anyways.

Are you aware that people decompress at a ppo of 1.6? No working situations but there is margin there.

I would like to hear SB experts opinion on using Air tables when diving nitrox. In my class i was specifically told to use Nitrox tables and make sure that i do not exceed MOD. I am currently reading a very good book "The last dive" by Bernie Chowdhury. There it was a very good story about guy who ignored Nitrox tables (he said that they are nonsense) and he died. I would recommend "experts" to read this book.

@ChuckP , yes I know aboput ppo 1.6 but i have a question whether you know what it is oxygen toxicity

 

[Strategist.]

One of the points in the nitrox class was to dive nitrox using air tables - added safety margin.

If you are not confident in your depth control or your awareness, you probably shouldn’t be diving that close to the MOD anyways.

Are you aware that people decompress at a ppo of 1.6? No working situations but there is margin there.

This is exactly what was shared to me as well. My instructor took the liberty to explain that is was one of the ways to trick the dive computer or increase NDL conservatism. Of course he also cautioned that in the process of doing so, we have to always bear in the the PO2 and MOD while diving. I appreciate the fact that the instructor took the liberty to help us develop into "thinking divers" that are able to discern between the pros and cons of the different approaches to diving as opposed to diving the way that some instructors decided to tell us just because its inherently safer.

 

[Efka76]

@boulderjohn , it would be very interesting to hear your opinion about actually diving on nitrox but having diving computer settings as "air". In my subjective opinion this is absolute nonsense and significantly increases a risk that diver might forget that he is diving on Nitrox and accidentally violate MOD and have serious issues (even drowning). However, the opinions above state that their instructors told them about such "tricks" and they are acceptable What is your view about such instructors teaching? Do they violate PADI standards?

I just reviewed PADI Ean materials and did not find anything that could support opinions above. It seems that some people are considered themselves "smarter" than others, PADI, TDI or other organisations, and like to add additional complications in places where fatal accidents can happen.

@ChuckP, according to PADI, when in recreational diving with Nitrox MAXIMUM ppo is 1.4. Contingency ppo is 1.6, however this is for emergency.

 

[lv2dive]

I don’t have an issue with diving air tables on Nitrox. The only “additional work” is remembering the MOD, and staying above it without computer alerts. My computer does not beep at me for anything (thankfully).

At the end of the day, i’d be much more concerned about a buddy who can’t trust themselves to stay above the MOD without alerts, than I would be about a buddy diving Nitrox on the air schedule.

Personally I dive a SW and set the accurate gas, and manage NDLs (or decompression) using the gradient factors I’m comfortable with. I would also dive 32% to 100 feet - keeps things simple for me.

 

[Strategist.]

@boulderjohn , it would be very interesting to hear your opinion about actually diving on nitrox but having diving computer settings as "air". In my subjective opinion this is absolute nonsense and significantly increases a risk that diver might forget that he is diving on Nitrox and accidentally violate MOD and have serious issues (even drowning). However, the opinions above state that their instructors told them about such "tricks" and they are acceptable What is your view about such instructors teaching? Do they violate PADI standards?

I just reviewed PADI Ean materials and did not find anything that could support opinions above. It seems that some people are considered themselves "smarter" than others, PADI, TDI or other organisations, and like to add additional complications in places where fatal accidents can happen.

@ChuckP, according to PADI, when in recreational diving with Nitrox MAXIMUM ppo is 1.4. Contingency ppo is 1.6, however this is for emergency.

If you want to quote me, please refrain from quoting me out of context.

This was what I said: "My instructor took the liberty to explain that is was one of the ways to trick the dive computer or increase NDL conservatism."

This was NOT what I said: "... the opinions above state that their instructors told them about such "tricks" and they are acceptable."

In no way, did I say it was acceptable. Just because it is one of the ways to trick the dive computer, does not equate to me saying that it is acceptable. In fact I followed on with the comment that, "I appreciate the fact that the instructor took the liberty to help us develop into "thinking divers" that are able to discern between the pros and cons of the different approaches to diving."

Again, your specialty is in reading in between the lines rather than following the entire argument. Please take the time to digest what the users are posting, instead of jumping the gun and shooting everything down for what it's worth.