Lite Nitrox at 145

[Scared Silly]

A personal data point, based on two trips to Chuuk on the Odyssey. There most everyone dives 27%. A few of the dives to the Hoki Maru one can hit ~145' in the holds, which puts one at 1.45 PO2. A bit high but one is usually in the hold for <3 minutes before exiting. At that point one spends the remaining time at shallower depths. So the 27% is for managing deco as one can finish the dive without any obligation.

I do not know the Moody wreck as to whether a similar profile can be done. It does not sound like it. So the above is probably moot for this specific site.

 

[steinbil]

What really gets me about discussions like these is the burning desire of so many posters to uncritically recommend their own controversial dive practices to other divers, especially when those divers are not trained/experienced for that kind of diving. What are you trying to prove?

I have much more respect for those divers who might do deep air dives themselves, without recommending it to others. Sure, if you want to take that risk for yourself, have at it. If you want to brag about it to inflate your ego, not ideal, maybe you'll lose a little respect, but it's still way better than explicitly recommending it to anyone and everyone.

If somebody is asking about diving outside of their own training, should we not as a community (a) encourage proper training and (b) recommend the safest way to undertake that type of diving, backed by science? Instead of beating our chests and saying "I've done it, so it must be fine" and possibly encouraging someone asking or reading this thread to do something that won't be fine for them...

 

[happy-diver]

If a competent diver person, No course, can take this bent blown up cracked finished forever pump

spend some time, ok lots of time, unbending unblowinguping uncracking unfinishing forever pump

every nut bolt seal and screw

I'll give the competent diver person, a free ticket to pump tanks with the pump without a course too


Your entire diving experience whether it be long or whether it not be long is only about the one dive

It's about the dive you are doing, it's about the plan you are making for the dive you are about to do

So you make your plan, and fall back plans, mix your gas programme your comp, write on your slate
so for the next week or two you study your plan read your slate do the dive on your head with good
conditions and bad and then all you have to be prepared for is the guy around the corner that didn't
do the prep, and the sharks

And there's life's course take it one dive at a time and know your gear and the guy around the corner

 

[Angelo Farina]

Do you have a citation for this? I'd like to read the studies because that conflicts with my understanding and experience. I'm not denying the contribution of CO2 to narcosis....just that "most" is the correct descriptor.

This was the main result of the research work done by Raimondo Bucher on deep coral hunters in the Med (diving down to 70/90 m in air) during the seventies. He published his results in a book.
Bucher also developed a protoypal first "offer" regulator for reducing the WOB, which later was licensed by Technisub (Spirotechnique, hence Aqualung) and became the Inject regulator, the very first one marketed explicitly for reduced WoB thanks to its venturi-driven injector.
It is all very old and very Italian, no surprise that nowadays this knowledge is almost entirely lost, particularly in US, where deep diving in air was never practised extensively as here.

 

[johndiver999]

What really gets me about discussions like these is the burning desire of so many posters to uncritically recommend their own controversial dive practices to other divers, especially when those divers are not trained/experienced for that kind of diving. What are you trying to prove?

I have much more respect for those divers who might do deep air dives themselves, without recommending it to others. Sure, if you want to take that risk for yourself, have at it. If you want to brag about it to inflate your ego, not ideal, maybe you'll lose a little respect, but it's still way better than explicitly recommending it to anyone and everyone.

If somebody is asking about diving outside of their own training, should we not as a community (a) encourage proper training and (b) recommend the safest way to undertake that type of diving, backed by science? Instead of beating our chests and saying "I've done it, so it must be fine" and possibly encouraging someone asking or reading this thread to do something that won't be fine for them...

Some people are constrained by economics, others by logistics and some by both. Helium is safer I am sure, but for many people, when they get up in the morning, their primary goal is not to live their life in the safest manner possible. If they did, then they probably would never set foot on a boat, let alone go underwater.

Diving on air or nitrox past 100 or 130 is decreasing the safety, but some people are willing to accept the danger and feel they can manage the risks and challenges. For me, the question is primarily where each person should draw the line.

I don't think it is necessary to prevent people from talking about how they dive- as long as everyone is free to criticize them as they see fit. That seems preferable to not allowing discussion of various dive practices.

I don't think of it as something to prove or brag about.