Scenario Ascending fromDepth

Scenario for deep divers-if you were say, 140 feet, and you had very little air left in your tank, and you had to make an emergency ascent, would you attempt to ascend quicker than normal to a shallower depth and allow yourself to outgass for a a few minutes, or would you opt to steadily (but quicker than normal, due to low air) ascend with no decompression stop? Thanx zeN||

I would stick very close to my buddy and hope he did a better job than I did in managing gas supply.

Regarding your ascent rate/offgassing question, a lot of that would depend on how much time was spent at max depth, and how long the total dive time was at the point of the low on gas realization.

Why would you make an emergency accent from 140ft or deeper
Deep or Technical diving uses redundancy techniques to prevent this ever happening.
Planning every step of the dive
The Rule of Thirds
Gas management and so on. Prevent ever running low on gas. Remember you have twin tanks with a manifold, in the event of a massive gas leak you can shutdown the manifold, this will give you easily enough gas to make it to your first Decompression stop. From there you are switching to Deco gasses in separate bottles anyway.

If doing deeper no Deco Diving, carry a Pony bottle with enough gas to bail yourself out !!

Thats kind of a tough one. Are we talking about solo diving or a hose that has bursted and losing air rapidly or just poor dive planning and not paying attention to your air consumption when you look down at your gauge and go oh sh*t im low on air. Hopefully your first choice would be goto your buddy for air if you have one

a good plan given by Cave Diver.

Cave Diver beat me to the punch, where oh where is your buddy?

OK, lets play with it and say your buddy just got swallowed by a giant whale and there you are at 140, your SPG says 0 PSI. What would I do? I would ascend as close to 60 feet per min as I could, knowing that on the way up I will gain enough air on an empty tank to get at least 4 - 6 good breaths from my tank as its air becomes available. (boyles law) Fast ascents are bad, remember that. A missed safety stop is not good, but not as bad as a fast ascent. I'm working under the asumption that this is not a deco dive. If this were, then you would most likely run a very high risk of a DCS hit and a chamber ride.

In reality I would feel a little panic and have to concentrate on the task at hand, not letting myself get focused on needing to surface at all costs. This in all honesty would be hard, but not imposible. Any divers who claims that they would not feel even a little panic is either dead or a liar. It's not a question of "if" you feel paniced, it's how you deal with it that counts. You learn to deal with it by practice, lots of practice.

I'd get my buddies attention, call the dive stick close with him and do a normal asent until I was at a safe depth to switch to my stage bottle or bottles and use back up tables for deco.
Rob

lal7176 once bubbled...
Thats kind of a tough one. Are we talking about solo diving or a hose that has bursted and losing air rapidly or just poor dive planning and not paying attention to your air consumption when you look down at your gauge and go oh sh*t im low on air. Hopefully your first choice would be goto your buddy for air if you have one

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I based my assumption on recreational divers, who should be within the 130' limit and had an "Oh S***" moment and dropped below their planned depth from lack of attention. Therefore there are no double tanks, no pony bottles, the only redundancy is your buddy.

Hopefully this wasnt a PLANNED dive to 140' because if it was then a low on air situation tells me the plan has already deviated. The divers in question should have left the bottom with ample gas supply to make a safe ascent.

And if it was a PLANNED dive to 140' then they should have had the appropriate redundancy and training to use it that a blown hose or leaking o-ring wouldnt pose a problem. You simply swim to your buddy, who should have ample gas supply if you planned properly, and make a slow safe ascent to the surface.

If you didnt plan the dive, if you arent diving with a buddy, and you dont have the appropriate training, experience or equipment to complete it, then it sounds like we have a new nominee for this years Darwin Award.

zeN|| once bubbled...
I'll have to take issue that you have to have a redundant air system to dive solo, period. It's certainly a good idea, and I use a pony on some dives and def at depth. <snip>
There are no hard and fast rules, but rather guidlines and personal choices, and levels of risk one is willing to take zeN||

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Your scenario -- Do you consider 140' "at depth?" If so, I would use that to do a normal slow ascent and whatever deco is indicated, since I planned my dive and my pony (or stage or reserve in my manifolded doubles) will adequately supply whatever gas obligations I have incurred. You are a strong advocate for solo diving, so for this scenario assumed that no buddy is available to bail you out.

This is a hypothetical case I'm working on: say you push your limits to 140 feet, whether you are solo or partnered up is irrelevant for this scenario, you are alone, or you can't get to your partner Gas is air. I can't be as particular about some details because I haven't done the math just yet. lets say your total dive time is c. 30-45 minutes, you will need a deco stop, you have several hundred pounds in your tank-would you attempt to ascend to say, 60 feet quickly, knowing the pressure changes between 140 ft and 60 ft will be less than the last 2 atmospheres, and ascend the last 60 feet slower, with a small deco stop, to allow outgassing- or would you stick to the book and ascend at 1 ft/sec , which in my scenario would leave you no time for a deco stop? This is a purely hypothetical case. Take a slow deep breath, (getting your pantys in a bunch over what you did wrong or what you should have done different is not allowed (it's hypothetical)); this is about dealing with an event you could find yourself in, and what choice you would make) Thanks for replies) zeN||

(no I actually don't reccomend solo-diving but I recognize some may accept the additional risks)