Detuned in this case means cranking the little adjustment knob on the end of your second stage to the most closed position it will go. This allows the spring to offer the most resistance to the force of the diaphragm opening the valve to let the air come through ... basically reducing the risk of free-flow as much as you can using the available adjustment.scubnewb wrote:OK what does detuned mean... oh and I was thinking about all of this yesterday and i was thinking to myself... well in a deepwater scnerio, wouldnt it be possible to shut the valve to slow or stop the flow all together so you have less stress and pressure to get to the top. I think that path of thinking came from watching the movie Sanctum the otherday and thinking about when the son takes the pony bottle and just takes the breathes off it he needs with no regulator at the end of the movie. Of course i thought well it is just a movie, but that doesnt mean its not possible. I dont dive deeper then 60ft unless i happen to wonder over the 60 mark and not notice then I turn right around... so at this point I would probably just run with a ascent as trained. But it is something that I was thinking about and wondering about.
Sometimes this will stop a freeflow ... sometimes not.
Sanctum was absolutely the most awful and unrealistic diving movie I've ever seen. Considering that James Cameron is a diver, I was superbly disappointed by how inaccurate it was.
When you open the valve on a tank, without a regulator, you're going to get air coming out at whatever pressure happens to be in the tank. Even on a small cylinder like he was using, you'd have to be extremely dextrous underwater to only open it adequately to not create a gush of air coming out. What he did looked easy ... it's not ... particularly not if you're doing it while wearing drygloves or heavy neo gloves, where you have little dexterity.
Don't try anything you saw in that movie at home ... you're liable to end up like most of the folks in the movie did ...
... Bob (Grateful Diver)