An age-old question: ways to 60m.

[grantmac]

Comparing any diving activity to DUI is stupid and insensitive to people who have lost loved ones to drunks.
You can't kill anyone else diving air or any mix, unless you are getting in the water relying on team bail out (which is debatable).

Air in the open ocean is a different creature than deep in a cave or wreck. It's different for different people.
Applying your cave centric, well funded gas needs to someone who wants to see a sponge at 60m IS stupid though.

 

[Boarderguy]

So, out of the symptoms of nitrogen narcosis, which one(s) do you experience?

Below is a list from DAN:

• intoxicated feeling
• impaired judgment
• difficulty concentrating
• drowsiness
• overconfidence
• euphoria
• fear and insecurity

There’s one more from TDI - visual narrowing. I read that as the opposite of ‘difficulty concentrating’.

Anyways, we can use the list from whatever certifying agency you trained with. I used the one above simply to provide a medically-vetted start point.

I have a mild intoxicated feeling when I initially cross 145 that passes by 150. I become a bit more aware of time constraints and the plan at 160 thru 180. At 190 my wob is noticeably more difficult than say at 130, but it's manageable. The narc at 190 is also much more in my face and physically feels like a drunkenness that I can't quite shake off though I'm still clear in my thought processes. Actions are also more deliberate vs my usual autopilot style of diving. I have yet to see 200 but that will occur once I spend more time in the 180-190 range.

Put that into whichever category(s) you see fit because it isn't just a single affect at every depth. Everyone is different and ymmv.

 

[Underwater Tourist]

I have a mild intoxicated feeling when I initially cross 145 that passes by 150. I become a bit more aware of time constraints and the plan at 160 thru 180. At 190 my wob is noticeably more difficult than say at 130, but it's manageable. The narc is also much more in my face and physically feels like a drunkenness that can't quite shake off though I'm still clear I my thought processes. Actions are also more deliberate vs my usual autopilot style of diving. I have yet to see 200 but that will occur once I spend more time in the 180-190 range.

Put that into whichever category(s) you see fit because it isn't just a single affect at every depth. Everyone is different and ymmv.

I wanted to mention to anyone reading this and wanting to try diving deep air, that there is astronomical individual variability in how someones body will react to deep air or scuba diving in general. I know a person who gets narked to oblivion at just 25 meters; similarly there are people who are fine at 50 meters. So please proceed intelligently and with care.

I also don't really have a dog in this fight, but just wanted to mention that I dove in peripheral EU a lot and deep air is more normalized there compared to the US. Dives to 40m are routinely done on air and noone is dying left and right.

 

[grantmac]

I wanted to mention to anyone reading this and wanting to try diving deep air, that there is astronomical individual variability in how someones body will react to deep air or scuba diving in general. I know a person who gets narked to oblivion at just 25 meters; similarly there are people who are fine at 50 meters.

Indeed I know someone who starts trying to donate gas to the fishes past 20m and others who do complex dives at 45m.
People rail against lowest common denominator training while ignoring lowest common denominator physiology.

 

[Underwater Tourist]

Indeed I know someone who starts trying to donate gas to the fishes past 20m and others who do complex dives at 45m.
People rail against lowest common denominator training while ignoring lowest common denominator physiology.

Personally, I think it's best that whenever a conversation about deep air comes up that the initial reply is to condemn it simply because when inexperienced or maybe recreational divers who don't know about gas density stumble on the topic, they get the message that its dangerous.

Once they learn and understand the dangers, they can make their own adult decisions about what level of risk they accept and how far they want to push things.

A different yet similar topic is solo diving, should it be condemned in scuba textbooks? Imho, absolutely yes it should. But then as you progress as a diver, you can choose what level of risk you accept and how you might mitigate it. Some of my most enjoyable and memorable dives were solo caves.

 

[old frogman]

Do I understand correctly that after TDI ANDP, there are two main ways to go deeper, down to 60 meters?

1. OC Trimix – Take a Trimix course (around 5 days), and then you're good to go. But each dive will cost you an extra ~$250 just for the helium.
2. CCR – Buy a CCR unit and complete MOD1, Helitrox, and Mixed Gas training (about 15 days total, spread out over time). After that, you're free to dive, and each dive costs around $50 for consumables.

Is that correct?

P.S.
I know about Extended range but I am not fill comfortable on air down to 50m....

It depends.

If you are looking at just a few deep 60 metres dive per year, OC Trimix presents the least risk and is the cheaper way to go.

If you are looking at doing numerous deep dives, that is, 50 plus dives per year, mixed gas CCR is the cheaper in the long run. However, CCR introduces numerous risks which may be partially mitigated with OC bailout.

Despite partial mitigation the ratio of CCR deaths to OC deaths is about 10 to 1.

Adverse events associated with CCR are as follows:
Complete or partial flooding.
CO2 absorbent failure.
O2 sensor failure.
Solenoid malfunction.
Controller malfunction.
Human error in CCR preparation, predive checks, monitoring during dive. Complacency with increasing experience can be a problem.

The problem with CCR is that some of the malfunctions may not be detected when they occur during the dive resulting in the diver being incapacitated to the point where he/she may be unable to take corrective action. This is despite carrying bailout gas.

In conclusion it boils down to how much risk you are willing to accept. I know people who have died on CCR, have gone back to OC and in some cases have given up diving altogether.

 

[crofrog]

yep, thanks for reminder - checked TDI reqs for mixed gas ~50 dives on given CCR... about 2 years with my diving realistically...

If you’re diving 25 dives a year just do it open circuit trimix

 

[crofrog]

Being impaired is such a weird thing to advocate for.

There is a possibility that he just can’t tell the difference between impaired and not impaired.

 

[Centrals]

Rebreather? Sound very interesting to me 25yrs ago. So I set off to do a easy course ie SCR. It was not difficult but I did find out the tediousness of diving/preparation even a simple SCR unit. There were a few critical pre-dive procedures which I have to pay close attention to them.
Rebreather especially CCR is NOT everyone cup of tea.

How to Tell if Closed-Circuit Rebreather Diving is Right for You

Is closed-circuit rebreather diving right for you? Here's how to decide if you should take a rebreather training course.

www.scubadiving.com

 

[FF / EMT]

You guys are making this way to complex, just free dive to 60 m, that’s the cheapest option…