Pony Bottle

[dumpsterDiver]

So, just to play devils advocate, wouldn't you think that people to whom all those conditions apply and are able to meet them, are probably the very same people who wouldn't really need a pony bottle in the first place?

Not at all. I view a pony bottle as insurance for gear failure, not as a crutch for irresponsible divers who simply run low on air (as I recently did).

 

[Dr Wu]

Answer: Because that is their right.

Learning to use a pony bottle is far easier than learning to work a BC. It is probably less dangerous too.

I bet a higher percentage of people have embolized due to uncontrolled bouyant ascents (which were precipitated by an inability to use a BC) than people who have been killed by screwing up with a pony bottle.

Agreed.

But again:

All divers need a BC.*

Some divers want a pony bottle.

Why not learn to use the necessary piece of equipment properly rather than concern yourself with something that is unnecessary?





*99.9% true

 

[Dr Wu]

"Dr" I am willing to entertain the notion that there is more than one way to achieve an end. I wish that you were equally open-minded.

Again you are claiming to "know" what I think.

You have no idea whatsoever. All you "know" is what I choose to tell you in my posts.

I am not going to correct you on this again.

 

[Cave Diver]

I am not going to correct you on this again.

Well that should certainly cut down on the amount of posts.

 

[Crush]

Again you are claiming to "know" what I think.

You have no idea whatsoever. All you "know" is what I choose to tell you in my posts.

I am not going to correct you on this again.

I am serious - I thank you deeply for that. Let's just hope that you stop "correcting" others as well.

Dear mods - if you want to ban me for a week or whatever you deem is appropriate you can - no hard feelings. I probably deserve it, but I can't help myself when faced by insurmountable ignorance.

 

[dumpsterDiver]

I guess that's the other extreme; what would take me 25-30cf DD can do with 6cf. Everyone just has to honestly assess their own capabilities and physiology and determine who they're closer to, if either. I don't imagine I'll ever get to DD's SAC level in an emergency--and if I'm lucky enough to have it my way, I'll never find out.

That's not true. My SAC rate is pretty high on a normal dive. Maybe 0.65 cu-ft/min, but then again I am pretty active usually. My SAC rate was probably pretty high during that last incident. I was EXTREMELY out of breath when it became hard to breath. My SAC at the time had to be 1.5 or more. NOT a good feeling.

Do your own calculations, but if you can get off the bottom at a rate of 60 feet per minute for the first 30-40 feet (not kicking, riding the BC), you are well on your way out of the deep and the actual air consumption will begin to slow...

So.... you are at 120 feet, you switch to pony bottle, you add a puff of air to the BC and you immediately begin your (non-swimming) ascent. In less than 40 seconds you are at 90 feet and if you slow the ascent rate to 30 feet per minute, you are now at 60 feet in another 60 seconds. In less than 3 minutes elapsed time, you could be at 40 feet.

If you experienced a low on air emergency (rather than total scuba failure), you should be able to sip the main tank for a while at 30 or 40 feet, even if it was hard to breath at depth as I did.

The problem arises in the calculations when you start to give yourself time on the bottom to sort things out and delay the ascent. The high SAC at depth is the problem. I guess you just have to do the calculations and try to determine what kind of contingencies you are willing to accomodate.

 

[dumpsterDiver]

Why not learn to use the necessary piece of equipment properly rather than concern yourself with something that is unnecessary?

Because the necessary equipment CAN fail at any time, even when used properly.

I view a pony bottle as a necessity for dives over 60 feet (for me anyway).

 

[Gombessa]

Do your own calculations, but if you can get off the bottom at a rate of 60 feet per minute...

The problem arises in the calculations when you start to give yourself time on the bottom to sort things out and delay the ascent. The high SAC at depth is the problem. I guess you just have to do the calculations and try to determine what kind of contingencies you are willing to accomodate.

It's not just staying at the bottom. As you stated about determining your own contingencies, that ascent rate isn't how I personally plan my reserve gas, so for my own needs I'd need significantly more gas to reach the surface. But if for some reason I suddenly found myself at 120ft with 6cf of gas, I'd likely shoot up initially at 60ft/min (or heck, faster) as well. Again, hopefully I'm never in a position to find that out.

 

[dumpsterDiver]

It's not just staying at the bottom. As you stated about determining your own contingencies, that ascent rate isn't how I personally plan my reserve gas, so for my own needs I'd need significantly more gas to reach the surface. But if for some reason I suddenly found myself at 120ft with 6cf of gas, I'd likely shoot up initially at 60ft/min (or heck, faster) as well. Again, hopefully I'm never in a position to find that out.

Hell I usually come up the first 30-40 feet at 60 feet per minute on a normal dive.

 

[Cave Diver]

Just for the sake of clarity, when I posted the number above, I used a 30fpm ascent rate.