Doing it Ridiculous

[Kim]

Kim -- What "massive 1st stage failure" is going to be solved by turning the valve off?
If the air in the tank is not going to be useable, I'd rather not be spending the time, energy, remaining breath in my lungs turning the valve off. There's either an alternate air supply to provide time to do mechanical mucking about (buddy, pony, isolated second tank), else it's time to do a Hail Mary ascent. Are you thinking about something like a first stage freeflow? What's the actual likelihood of that clearing by one or two on-offs? (risk/benefit -- since it takes multiple turns on the valve to shut it off, we're talking a serious number of seconds here. I'd personally hate to spend 10 seconds of my last breath trying to turn the valve off then on again, only to find I'm still hosed, that it was an o-ring blowout or some such, not cured by an on/off)

(I'm asking this out of real curiosity, a serious question, trying to understand a major failure that's going to deplete your tank in seconds, yet can somehow be cured by turning the valve off, and the remaining air in the tank will somehow then become accessible again.).

Mark - the point is if there is no air left in the tank there is nothing to use. In cold water as Mike said it could be a first stage freeze that will clear quickly if shut down. It could also be an o-ring blow out - internal or main tank ring. Shutting down the tank means conserving what's left in it before the first stage comes into play. In a free flow situation you can get air through the flow, turn it off, ascend a bit blowing your bubbles to keep your air passage open, turn it on and repeat. Even if the first stage is completely unusable because of a tank O-ring for instance you can breath directly off the tank by feathering it in the same way.
Now I'm not saying that this is ideal...it's not. The point is that if you can turn your tank off (and then on again) quickly enough to save the remaining air in it, it gives you more options to try. If the tank is empty and there's not another one close....you'd better hope that what's in your lungs will get you to the surface.
IMO being able to reach your tank valve is important using a single tank - or doubles. Even the other one Mike mentioned - jumping in with your tank turned off - can be a death sentence if you can't turn your tank on yourself. I believe this latter one has actually happened to quite a few people. Think about it....drowning with a completely full tank of air strapped to your back!

edit: Mike already seems to have addressed it.

 

[MikeFerrara]

Ahh, but you're in the tech zone, multiple bottles and regs.
For a normal OW diver, single tank, no deco obligation, I would expect to go to breathing from the bubbler, immediate ascent, controlled. Good to be able to reach your valve and try feathering in such a case? Sure. Life or death (or serious bends risk)? I'd expect not -- this shouldn't be an empty-the-tank-in-seconds scenario.
(Actually, I'd personally go to my pony, but that's cause I'm a wimp, don't play in deco land.)

As I said in my last post, the value for a single tank diver is probably more in being able to turn it on than it is turning it off. I can't see ANY advantage in have a valve that can be turned off and not being able to turn it back on.

Another thing to take note of is that one of the methods commonly taught to recover a lost reg requires that you be able to reach back and find where the hose goes into the reg and follow the hose to the reg. Not having floppy equipment eliminates the problem but that arm sweep thing is just about useless unless your vertical and not in any current or moving. If you can reach the reg you're pretty close to being able to reach the valve but you can't do either with the valve half way down your back like I see some divers wearing it.

 

[Kim]

I would expect to go to breathing from the bubbler, immediate ascent, controlled.

And 99% of such situations you probably could. It's the other 1% that might kill you unless you have another trick up your sleeve.

 

[do it easy]

Ahh, but you're in the tech zone, multiple bottles and regs.

I also had a reg free flow at 100' while I was wearing a single tank. Buddy and I did an air sharing ascent. The reg was bubbling away and it would have calmed things down to be able to turn it off. Of course it did run out underwater, but for some reason, it wasn't so calming when the bubbling stops because the tank is empty.

 

[markfm]

Good inputs, thanks. That's why I ask questions -- understand the logic chain.
(Of course, it almost feels cheating to seek real information in this thread -- though left in Basic Scuba Discussions, the title is inherently Whine and Cheese )

 

[lamont]

Another thing that a tank shut down can do to help you, is when you hit the surface you can hit your inflator and turn the valve on and inflate your BC/Wing with the remaining gas. That means that if you're breathing off your buddys long hose / octo you can keep that reg in your mouth and don't have to manually inflate. In rough seas this could reduce panic and reduce chances of aspirating water.

Generally, if you manage to shut down the valve and keep some air in your tank that gives you some more options, which I'd view as always being a good thing. Letting the tank drain dry reduces options and that's generally less optimal.

 

[mer]

Well I was at Buddy Dive in Bonaire last week and I didn't see one long hose

There were two of us 100 yards south at Bari Reef, two at the Plaza, and DIR videographer at Capt Don's 100 ft North .. so really, you were surrounded. We just tend to keep out mouths shut on the dive dock.

 

[TheRedHead]

There were two of us 100 yards south at Bari Reef, two at the Plaza, and DIR videographer at Capt Don's 100 ft North .. so really, you were surrounded. We just tend to keep out mouths shut on the dive dock.

Hey, I dove Bari several times from the Buddy dock and didn't see you. I couldn't believe the number of Biofins and Atomic splits I saw there. Buddy must attract an older crowd as most of the divers were over 40 and some even in their 70s. I saw one BP/W and several people with ponies. I've never ran into a DIR trained diver on any of my dives - anywhere. All the long hose divers whom I've dived with, and have enjoyed diving with, were all cave certified.

All I can say is that the amount of incendiary comments on both sides of the fence, which I quickly found Googling, have done nothing to promote DIR principles.

 

[GDI]

Hey Rick, last time I was at Peacock JJ was there with a crew teaching a cave class. The whole group was too busy to give any one a hard time and getting in the same time we were. We had planned on running a line down that little side tunel to the well. You know the one...right inside the cavern entrance? I was running the line and I did tell my wife...to let me know if they got behind me with the video. LOL. One of my wifes backup lights even has a switch, can you imagine? And no one said a thing. I was caught dead to rights with rock boots (the whites boot actually) and I was never attacked.

And this is pretty much the norm

 

[rmannix]

Was outside the last few hours battling autumn leaves in my yard. My neighbor across the street was doing the same thing.
While neither of us are truly "DIR" he had a gas-powered back-mount leaf blower that was minimalist in nature while I used a Sears Craftsman 2 speed electric blower. While his has a higher flow rate, I was unable to outbreathe either one, and there was less heat and vibration on the electric model. I got mine used at another neighbors yard sale even though Home Depot strongly recommended a new one.
He had a short hose that made it difficult for me to use while he was wearing the backback and we found 2 trees that we couldn't fit through sharing his rig.
Both rigs have advantages and disadvantages. Ease of starting, less maintenance and quieter for the electric, higher mobility and able to use during blackouts for the gas model. Danger of electrocution with the electric and highly flammable gasoline on your back with the gas model. We both had rakes as backups, I prefer metal over the new plastic ones.
I asked if his rig was 2 or 4 stroke and he got somewhat offended and remarked that he was blowing leaves when I was in diapers, which I kinda doubt being 4 years older than he is and haven't worn diapers for months now since I installed a pee valve on my favorite jeans.
I plan to get a longer extension cord for mine, with the cord around my neck it got a little tight at the far corner of my property. The cord has the added benefit of helping me find my way back to the garage in low visibility. The wind can be unpredictable and many leaf blowers in this area have been swept away. Luckily most get rescued only hours later by their wives after being found in bars not too far away.
I believe bagging vs. mulching was covered in another thread.