Deep Air Poll. Well, Someone Has To Put Their Head Over The Parapet...

[Bob DBF]

I'm working in the 150' range for a project now. Back when I was young and dumb, 200' was not uncommon and for a lot less reason than I need now to break 100. Being a fat old man with a little to live for has changed my attitude towards dives a bit. Fortunately I know a number of younger divers that think some of the gear and conditions I will dive are crazy, so I don't feel too bad overall.

I believe that Deep Air is work and should be treated accordingly.


Bob
-------------------------------------
I may be old, but I'm not dead yet.

 

[Kevrumbo]

For upcoming Bikini Atoll Trip, Oxygen costs will be $0.06/litre and Helium $0.20/litre ($1.70/cuft for O2; $5.66/cuft for He).

I plan on doing nearly 20 dives over 11 days on the M/V Windward Liveaboard (multi-place Recompression Chamber included onboard, but not DAN approved), using Eanx50 & Oxygen for deco gases --and Deep Air & 20/20 Trimix as needed for penetrations 45m and deeper.

Guesstimate Open Circuit Total Gas Costs to be over $3k.

 

[AfterDark]

I've done it in the past, haven't done for a while now unless 130fsw counts. The deepest was 170' and that was only a bounce dive. There are a few wrecks here in NE that are deep the Bass @ 160fsw and a few others and of course the Doria which these days you'd have to own your own boat to dive her on air. Round here even in the summer the bottom is usually dark and cold which just makes the narc worse.

 

[pocky21]

I'm better when I'm narced

 

[elmer fudd]

I've done up to 135' on air, but nowadays I pretty much limit myself to 100' or less. I find that for me, in the environment that I dive, (cold dark water), narcosis tends to bring on feelings of panic and impending doom and I don't like it at all. I've never actually panicked and bolted for the surface, but I have been freaked out to the extent that I believe I wasn't thinking rationally and could easily have become a liability to my buddy.

I may do it again in the future, but anything over 120' I'd like to work up to in a series of dives. That panicky dark nark sensation is something that I need to overcome first and I don't think I'll ever be one of those divers that goes beyond 165' on air.

Clear warm water might change my perspective on things though.

 

[Rhone Man]

I am comfortable diving deep air to about 180' or (in a pinch) 190' in the right conditions. But I am amply aware of the impairment that this causes me, and so I try to limit it to (i) benign conditions, and (b) sites that justify it.

 

[Tortuga68]

In the Philppines, where I do most of my diving, over the last 3-4 years I'll regularly do dives up to 215'/65m on air (doubles) usually with EAN50 and O2 for deco (although sometimes just O2, or even just backgas). These are all OW, warm water dives with good viz. More recently I will sometimes do 150-180'/45-55m as the first or second dive of a trip; narcosis doesn't usually bother me for this even if I've been out of the water for a few months.

During my training I would get various narcosis symptoms including visual and aural hallucinations, paranoia and euphoria, but that's uncommon now - I knida miss the euphoria but not the others. Worst dive was probably a training dive to a target depth where we missed the bottom and were just hanging there in low light at (IIRC) about 215'/65m... creepy. Later on I did another dive to that same depth and my buddy went deeper (recovery dive) and I was sitting there on my own - very creepy!

I have done a dozen or so dives between 215'/65m and 330'/100m on air but now wouldn't go beyond around 250-280'/75-85m because there's really nothing to see in Puerta Galera any deeper than that. For these dives I would always do some sort of work-up.

On the above dives we do some short swim-throughs but for any sort of serious overhead/penetration I would use trimix deeper than 130'/40m (have normoxic trimix this year and planning a wreck dive trip; previously had no reason - IMO - to get trimix certified).

 

[ajduplessis]

I will dive down to 150-160 on air, nothing more. Any deeper and I use helium in breathing gas with END of ~130ft. If helium is not available/expensive I will not descent below my air limit. Cave diving the max is 130ft on air if I am familiar with the systems, if not 100ft max.

 

[Ste Wart]

I blame Ste Wart, since he suggested it in the current, never-ending deep-air thread.

Why not everyone else does

For the record now that I dive in the UK I don't do deep air anymore, this is possibly the reason I'm broke this month as two mix dives do not combine well with my salary! However when I visit the clear warm blue waters of Egypt again, I would happily dive Air up to 50msw.

EDIT: Deepest is 63msw on Air. I spent the whole dive constantly asking myself if I was narced. Which at the time I thought was a good thing, now I wonder why I was talking to myself

 

[waterpirate]

For upcoming Bikini Atoll Trip, Oxygen costs will be $0.06/litre and Helium $0.20/litre ($1.70/cuft for O2; $5.66/cuft for He).

I plan on doing nearly 20 dives over 11 days on the M/V Windward Liveaboard (multi-place Recompression Chamber included onboard, but not DAN approved), using Eanx50 & Oxygen for deco gases --and Deep Air & 20/20 Trimix as needed for penetrations 45m and deeper.

Guesstimate Open Circuit Total Gas Costs to be over $3k.

That is a really good advert for going with a rebreather.
Eric

---------- Post added June 4th, 2013 at 02:23 AM ----------

I have dove deep air, but have not had bicycle tire gas in any of my tanks since 2006. If nitrogen is the boogy man, reduceing that percentage by inserting higher o2 or helium just makes sense to me. I choose to not dive deep, 150 plus if the logistics and or finances negate helium usage.
Eric