Purging, Pony's and Panic

[00wabbit]

That is the way I used to do it. My concern is in an emergency you might not have a breath full of air in your lungs to purge with.

From now on I am purging with the purge button. That is the muscle memory I want to have.

 

[Abdullah]

... but, is it taught to press the purge when switching from one second stage to another? I would think that is unnecessary in most situations and could initiate a freeflow in some situations..

I think it depends on how well the diver can control his buoyancy during the gas switch. If he's trying to hold a depth, a big deep breath might pop him up. Whereas pressing the purge keeps the diver neutral.

Also, having the pony along is an insurance policy against an OOA. In a real OOA emergency, the diver may not have a full breath available to purge the pony's reg. If he's practiced the switch using the purge button, he won't need to do anything different in an actual emergency.

 

[TSandM]

It's not much of a push of the purge button that is necessary.

When we do valve drills in doubles, we're taught to purge the reg we are about to switch onto, so we are sure there is gas there and it is working. It's just a little "pop" of the purge button. I've yet to see it induce a freeflow, although I might be more worried under ice.

 

[Darnold9999]

I would also add a "check/open the valve" portion to your practice for the emergency switch when you have also forgotten to open the pony valve - or as many do, dive with it closed.

 

[00wabbit]

Noted. Since I use this as a pony I keep the valve open for the entire dive.

 

[ppo2_diver]

Noted. Since I use this as a pony I keep the valve open for the entire dive.

When diving a stage with the valve fully open, you run the risk of a free flow draining the bottle and you may not know it. Become proficient with the stage and its switching orocedures and you won't need to worry about leaving it open.

 

[00wabbit]

Noted. My reasoning is that since this is in front of me I would know if it was freeflowing.

This weekend I bumped the reg once while entering a swim through and immediately realized the reg was blowing bubbles. What is the risk of water backing up into the first stage if the stage was off and I bumped the purge like that?

I do remember when I was sucking water that I did try the knob on the bottle to make sure it was open so I am pretty sure I could manage the same if I was truly out of air. Which wouldn't happen unless I had an equipment failure.

 

[616fun]

You are missing the point of your issue. I've never (or rarely) use a purge for a gas switch. The amount required to clear a reg is so small that it can be done even with next to no gas in your lungs. You follow the lung purge by a slow and careful draw on the reg to breathe over any water left in place. Don't make the purge your fail safe for poor technique to begin with.

 

[00wabbit]

Noted - So what would be the textbook technique for switching regs?

In OW class they show you purging with the button and purging with your breath but didn't really lay out one vs. the other.

If I'm going to be practicing I want to practice the right thing.

 

[616fun]

As I stated above. Blow the reg clear then breathe slowly over the water (if any is left). That should be covered in OW.

Purge isn't in itself an issue and can be used, but you'll rarely find divers doing gas switches using it. The only thing I use purge for is to get my regs off my tanks after shutting the valve down.

The bigger issue you are dealing with in this issue is task loading and dealing with a rising set of circumstances. We've all sucked in water. What you do after is key. Nice work keeping a level head. Practice makes close to perfect (there is no perfection) and thinking thru each situation will make you and solid and safe diver.