CuzzA
Wetwork for Hire
A more practical scenario is the failure of your deco reg. Do you extend your deco to finish on back gas or just go ahead and swap regs and finish as planned?
DumpsterDiver emergency ascent from 180'
- Thread starter 2airishuman
- Start date
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I would feather the valve and breathe my deco gas until I either finished my stop or ran out of deco gas. If I ran out, then I would switch to back gas and wait for my buddy (who would be carrying my deco gas emergency reserve) to finish his deco and pass me his deco bottle in order for me to finish my deco. If we had multiple stops to go, I would just take his deco reg after he finished the current stop, do my stop, then switch back to back gas, ascend to the next stop, repeat. But, feathering the valve should carry me long enough to get up to the last stop, in most cases, I would think.
I hate to ask because you guys are going to treat me harshly, but would a Y-valve have any application in this incident? Obviously no redundant gas but reasonable hardware redundancy by just using another 1st stage and octo. I have this one but haven't dove it.
Not sure about a y valve, but an H valve would do the trick nicely. Of course, that assumes one services their gear regularly and does appropriate pre-dive checks. Otherwise you just have double the number of crappy regs waiting to fail at depth, plus probably a failure in the H valve itself. ;-)
H and y valves are great for situations like this...if you can reach the valves when the stress level goes through the roof.
Y valves are a rarity these days...even though they hold significant advantages over h valves.
Y valves are a rarity these days...even though they hold significant advantages over h valves.
lermontov
Contributor
Is there any difference between a Y and an H valve other than the shape? I mean, don't they work the same way?
I'm no expert, but it just seems to me that the value of a Y or H valve is really for people diving single tank in really cold water. In really cold water, you are more likely to get a 1st stage to freeze up and free flow. In that case, shutting down that side and breathing off the other side is a good capability to have.
But, in warmer water, the 1st stage isn't going to freeze. So, the Y/H is just insurance against the exact kind of problem that DD had - i.e. blowing a HP seat. In that case, a Y/H valve just seems like a bit of gear to instill false confidence. If you blow a HP seat and you're diving a single tank, by the time you get the valve shut down, depending on where you are in your dive, you could easily have lost enough gas to be below your appropriate minimum reserve. So, it just seems like if you're doing a dive in warm water and you think you might need the redundancy afforded by a Y/H valve, it probably really means that you need the full-on redundancy of double tanks.
That is somewhat based on THINKING that a blown HP seat will dump gas faster than a frozen/freeflowing 1st stage would. I could be totally wrong on that, though.
If it even saved 700psi wouldn't that have been enough to get back to the surface or make that pony bottle last long enough for a proper safety stop? It might be pointless at the end of a dive that blows a seat but what if it just creeped up and started to freeflow? Any advantage is an advantage even if it's a small advantage.
Back to the actual discussion of DD's incident, my earlier post started me thinking.
Wouldn't it have been smarter for DD to shut down his tank valve immediately, rather than continuing to breathe it until it ran out? Or, possibly, inject some gas in his BCD, to get a little positive and start his ascent, and then shut it down. Either way (it's only maybe 2 seconds difference), the point being not to leave it open until it ran out.
Example:
- hear reg blow
- grab inflator, push button and hold it down
- immediately begin valve shutdown
- once valve is shut, release inflator button
- grab pony reg and prepare to exchange
- if you still hear bubbles, then you know it's a blown tank valve O-ring, so re-open the tank valve and keep breathing off the tank until it's empty. No point in letting Neptune have ALL that gas. Conserve the pony bottle, in this case.
- if the bubbles have stopped, 2nd stage in mouth should already be breathed out because of holding down the inflator button
- exchange regs immediately (if bubbles stopped)
- return hand to inflator and begin to vent to control ascent
- stop at 15'. If pony runs out, start feathering the tank valve and breathing off that (assuming there's any gas left)
If he was neutral when it blew, maybe the inflator part is optional. A little bit of a swim up and he'd be positive anyway.
I'm thinking that with the cool-under-pressure that DD displayed this whole process would be complete in 4 seconds or less. Assuming he can reach his tank valve, of course. So, he would easily be positively buoyant but preventing himself from corking all the way to the surface. And he would get to safety stop depth still with most of his gas in the tank (assuming it was a blown HP seat and not a blown tank valve O-ring).
Wouldn't it have been smarter for DD to shut down his tank valve immediately, rather than continuing to breathe it until it ran out? Or, possibly, inject some gas in his BCD, to get a little positive and start his ascent, and then shut it down. Either way (it's only maybe 2 seconds difference), the point being not to leave it open until it ran out.
Example:
- hear reg blow
- grab inflator, push button and hold it down
- immediately begin valve shutdown
- once valve is shut, release inflator button
- grab pony reg and prepare to exchange
- if you still hear bubbles, then you know it's a blown tank valve O-ring, so re-open the tank valve and keep breathing off the tank until it's empty. No point in letting Neptune have ALL that gas. Conserve the pony bottle, in this case.
- if the bubbles have stopped, 2nd stage in mouth should already be breathed out because of holding down the inflator button
- exchange regs immediately (if bubbles stopped)
- return hand to inflator and begin to vent to control ascent
- stop at 15'. If pony runs out, start feathering the tank valve and breathing off that (assuming there's any gas left)
If he was neutral when it blew, maybe the inflator part is optional. A little bit of a swim up and he'd be positive anyway.
I'm thinking that with the cool-under-pressure that DD displayed this whole process would be complete in 4 seconds or less. Assuming he can reach his tank valve, of course. So, he would easily be positively buoyant but preventing himself from corking all the way to the surface. And he would get to safety stop depth still with most of his gas in the tank (assuming it was a blown HP seat and not a blown tank valve O-ring).
I need to repeat again that it is possible (and and shows good judgement) to make actual contingency plans for dives to this depth, or to any depth for that matter.
On the surface of it, saying, "any advantage is an advantage even if it's a small advantage" sounds axiomatic but there are better ways of going about this. Contingency planning does not need to be an intuitive process. What DD does isn't turning a small advantage into a win, as I mentioned before. His approach is "Jesus take the wheel" and he worms out of it using skills (which he does have) instead of judgement (which he does not).
Once again, I would like to point out to the less experienced people following this thread that the approach to safety of the diver in the video is haphazard, complacent and dangerous. If you want to learn more about contingency planning then ask the question in a new thread and we'll try to jump in.
R..
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