Deep Air

[HowardE]

sure you do. you could get the training to do these dives safely.

What is your basis for calling these dives unsafe? Anecdotal, or personal experience?

 

[Diver0001]

I routinely dive in the 100-140 range on air (I've done many hundreds of such dives) and I can function more or less unimpeded up to about 120 and accomodate it up to 140 without any trouble on most dives/days.

However, I don't think is what Rhone Man meant by deep air. I think he was talking really deep. The deepest I've been on air was about 200 (I think LOL) and I was pretty darned narced. I've noticed that after about 120 I find the narc gets exponentially worse the deeper you go. I still dive to 165 from time to time for the fun of it but conditions have to be good (tropical) because I'm not overly confident much deeper than that because of the narcosis. Diving to the 200 range is definitely not something I would consider doing on air. Once was enough for that.

Frankly I have no idea how divers like Gilliam made some of the dives he made. His tolerance for narcosis is either extremely high or mine is extremely low but I think I'd be unconscious well before hitting 400ft if I tried a stunt like that.

R..

 

[rjack321]

N/M Wrong article.

Was this the ascent from 250?

Planned to roughly the same depths electric_diver considers "safe" on air. He toxed at 190ft on air after the bounce down to 250.
The Deco Stop

 

[FishDiver]

There is a huge community of divers in Australia that routinely dive to 55 meters on air. There are a number of wrecks in Sydney Harbor in the 45-50 meter range.

The community consists of divers with one thousand+ dives and places far more emphasis on mentoring than formal training. Few use trimix for dives of less than 55 meters. I have done over 400 dives with these people and can count on one hand the number of nitrox tanks I have seen on a boat.

I am not claiming this is optimal but it is common.

 

[syntaxerrorsix]

Planned to roughly the same depths electric_diver considers "safe" on air. He toxed at 190ft on air after the bounce down to 250.
The Deco Stop

Seems that we need to identify the topic then. It seems to be bouncing back and forth between pushing ppo2's, narcosis, or both. Narcosis is subjective no matter how many times it's been debated and pushing ppo2's for the hell of it seems silly. I however don't fall into the 30M END camp that seems to be gaining ground with those with a large checking accounts, certain training organizations or those with no availability problems because they never dive anywhere that doesn't mix.

I agree 250FSW on air dependent on duration is unwise however. I think we just need to be more definitive.

BTW thanx for the link.

 

[Rainer]

Are you trimix certified?

Seems that we need to identify the topic then. It seems to be bouncing back and forth between pushing ppo2's, narcosis, or both. Narcosis is subjective no matter how many times it's been debated and pushing ppo2's for the hell of it seems silly. I however don't fall into the 30M END camp that seems to be gaining ground with those with a large checking accounts, certain training organizations or those with no availability problems because they never dive anywhere that doesn't mix.

I agree 250FSW on air dependent on duration is unwise however. I think we just need to be more definitive.

BTW thanx for the link.

 

[syntaxerrorsix]

Are you trimix certified?

Nope.

That however has no bearing on whether or not I feel comfortable at 150FSW on air. All that tells you is that I've not dived the alternative. Once again, subjective.

 

[Rainer]

If I'd never driven sober, I might feel real comfortable with a BAC of 0.08 all the time. Doesn't mean it's the best way to handle road conditions, though.

I'm just saying, hard to have strong opinions until you've at least tried some deeper dives on trimix. I certainly know I have a clearer head with He in the cylinders. In any case, it's NOT about how you feel on any given dive. It's really about how you'd respond in an emergency, to novel situations (basically the entire point of "tech" training; it's not like breathing trimix is any different, really, than breathing air). I stack the deck in my favor with helium.

Nope.

That however has no bearing on whether or not I feel comfortable at 150FSW on air. All that tells you is that I've not dived the alternative. Once again, subjective.

 

[LiteHedded]

What is your basis for calling these dives unsafe? Anecdotal, or personal experience?

just my opinion that an END of 180' is dumb.

 

[syntaxerrorsix]

If I'd never driven sober, I might feel real comfortable with a BAC of 0.08 all the time. Doesn't mean it's the best way to handle road conditions, though.

I'm just saying, hard to have strong opinions until you've at least tried some deeper dives on trimix. I certainly know I have a clearer head with He in the cylinders. In any case, it's NOT about how you feel on any given dive. It's really about how you'd respond in an emergency, to novel situations (basically the entire point of "tech" training; it's not like breathing trimix is any different, really, than breathing air). I stack the deck in my favor with helium.

Are you telling me that every dive I did above 98FSW isn't consider sober diving? That in all those situations I could have performed better with helium? I can in fact compare how I feel and react at 60FSW to what I do at 150FSW. It's not like breathing trimix is different it's more like the cost and availability is different. I'm not pushing ppo2 limits with the diving that I'm doing therefore assuming I'm not sober by your preconceived notion of narcosis is still subjective. I do agree that deeper diving benefits greatly from helium, I just don't think that 10FSW is the start point.