Probably stupid question from a non-RB person

[formula1mb@aol.com]

I have never understood having a BOV plumbed to a tiny onboard tank but that's a different issue.

Correct me if I'm wrong but from the reading I've done, the point of having the BOV isn't for a permanent solution but simply so you can get your breathing rate under control if you take a CO2 hit. From others I've heard stories about how when you have a huge CO2 buildup, it's almost impossible to hold your breath long enough to switch to another regulator without swallowing a ton of water.

So if you have the BOV even to a small onboard tank, you won't hesitate to bail out because of your out of control breathing and fear of swallowing water. Than once you take some sanity breaths you can switch to a larger bailout. Or of course if it's a simple rec dive, you can just do a safe ascent.

 

[limeyx]

Correct me if I'm wrong but from the reading I've done, the point of having the BOV isn't for a permanent solution but simply so you can get your breathing rate under control if you take a CO2 hit. From others I've heard stories about how when you have a huge CO2 buildup, it's almost impossible to hold your breath long enough to switch to another regulator without swallowing a ton of water.

So if you have the BOV even to a small onboard tank, you won't hesitate to bail out because of your out of control breathing and fear of swallowing water. Than once you take some sanity breaths you can switch to a larger bailout. Or of course if it's a simple rec dive, you can just do a safe ascent.

That's "one way" to do it not very scalable to deeper depths though, as you will only get a few breaths from those small tanks, so as soon as you bailout, you are instantly looking for new gas...

 

[rjack321]

That's "one way" to do it not very scalable to deeper depths though, as you will only get a few breaths from those small tanks, so as soon as you bailout, you are instantly looking for new gas...

Would be rescuers will probably exhaust a little 13-19cf dil bottle if they purge much during ascent/exit as they try to keep the airway/mouth water free too. And then they'll be faced with continuing the ascent/exit or stopping to try and put a different OC reg in the victim's mouth.

 

[Cave Diver]

That's "one way" to do it not very scalable to deeper depths though, as you will only get a few breaths from those small tanks, so as soon as you bailout, you are instantly looking for new gas...

And thats why I carry a spare air so I can make it to the surface!



It's a joke people!

 

[Cave Diver]

I don't see the point of doing a dil flush for someone else. Yes it corrects a hypoxic loop but the loop is hypoxic for in all likeihood not having O2 (off or empty) so its at best very temporary, they might sorta wakeup but they'll need to be on bailout anyway. It could reduce ppO2 long enough to allow them to stop seizing but only if the original fault in the O2 add is somehow corrected (unlikely while they are unconcious) so again what is the dil flush doing for the injured diver & rescuer? It does keep the mouthpeice in, but its just delaying the inevitable OC (or BOV) reg needing to be in their mouth.

The main thing it does is that it puts a known, breathable gas into the loop whether the victim is suffering from Hypoxia, Hyperoxia, or Hypercapnia. You may not know what is wrong with them, but if they still have the loop in their mouth and you do a dil flush, at least you know they have a breathable gas right now.

The best choice is to get them off the loop and on to OC bailout. When in doubt, switch to bailout.

However, not all units have a built in bailout out, so switching requires removing the loop from their mouth, closing the loop and giving them an OC reg. Knowing exactly what their bailout procedure is and how it works should be an important part of pre-dive planning.

Other things to keep in mind during all of this is that if you do a dil flush and and you're not venting the counterlungs while you're adding gas, you're going to create a drastic increase in buoyancy and you could send them rocketing to the surface.

Or, if they have a separate bailout and you take them off the loop and fail to close the valve, the loop could flood making them extremely negative.

All of that adds to complexity of a rescue and needs to be discussed prior to jumping in the water.

 

[rjack321]

The main thing it does is that it puts a known, breathable gas into the loop whether the victim is suffering from Hypoxia, Hyperoxia, or Hypercapnia. You may not know what is wrong with them, but if they still have the loop in their mouth and you do a dil flush, at least you know they have a breathable gas right now.

The best choice is to get them off the loop and on to OC bailout. When in doubt, switch to bailout.

However, not all units have a built in bailout out, so switching requires removing the loop from their mouth, closing the loop and giving them an OC reg. Knowing exactly what their bailout procedure is and how it works should be an important part of pre-dive planning.

Other things to keep in mind during all of this is that if you do a dil flush and and you're not venting the counterlungs while you're adding gas, you're going to create a drastic increase in buoyancy and you could send them rocketing to the surface.

Or, if they have a separate bailout and you take them off the loop and fail to close the valve, the loop could flood making them extremely negative.

All of that adds to complexity of a [-]rescue[/-] recovery and needs to be discussed prior to jumping in the water.

close so I fixed it for you

 

[TSandM]

Yes, my biggest take away from the times I've dived mixed teams, and from talking to Mel the other night, is that my OC stuff is so SIMPLE!

 

[muddiver]

My air hat is even simpler (from the divers perspective). The diver doesn't need to monitor gas supply, bottom time, ppO2, MOD, END, etc.....