40cf too big for pony?

[doctormike]

Just bought a Pony....never dove with one. I assume I can fill it with Ean as well?

Same rules as for any other tank. If you get it filled at a place that does partial pressure blending, it needs to be O2 clean.

If you are using it as a pony for recreational diving, then just fill it with air and don't worry about making it O2 clean. Unless you have an emergency, you are not going to be breathing it, and if you do have an emergency, the fact that you are suddenly breathing a leaner mix than your EAN backgas isn't going to make much of a difference since you are just ascending at this point and you shouldn't have a deco obligation.

If you are using it as a stage bottle, then it would make sense to fill it with the same mix as your backgas (I'm assuming EAN) so you don't have to switch your computer and so you will get the advantage of less nitrogen loading for the part of your dive where you are breathing from it.

 

[MaxBottomtime]

I "drain my main tank" down to about 300 lbs prior to beginning an ascent (that's an average, more or less depending on depth), usually end up with about 250 at my safety stop and 50 psi after my safety stop. The pony isn't actually "used" to extend the dive, the dive is extended because little to no reserve is kept in the main tank, because the pony IS the reserve. On rare occasion when I've gone to the pony I have done it long before I get anywhere close to draining the main tank, because when I switch to the pony, now the main tank is the backup and I'd want at least 750 psi in there prior to starting an ascent from depth.

This is the exact reason I no longer allow pony bottles on my boat. A dive buddy of mine has run out of air twice. In each case he drained his pony before going back to his primary and draining it, just to get a few more minutes of bottom time. In each of those occasions his pony allowed water to enter. I watched as the dive shop emplolyee opened the pony and showed me three inches of water inside a 19 cu ft tank.
Diving with a pony seems to give some divers a false feeling of invincibility, knowing they have a security blanket in case they run out of air. I told my buddy to watch his spg so he no longer runs out. He will no longer be my buddy if he gets a third strike.

 

[ajtoady]

This is the exact reason I no longer allow pony bottles on my boat. A dive buddy of mine has run out of air twice. In each case he drained his pony before going back to his primary and draining it, just to get a few more minutes of bottom time. In each of those occasions his pony allowed water to enter. I watched as the dive shop emplolyee opened the pony and showed me three inches of water inside a 19 cu ft tank.
Diving with a pony seems to give some divers a false feeling of invincibility, knowing they have a security blanket in case they run out of air. I told my buddy to watch his spg so he no longer runs out. He will no longer be my buddy if he gets a third strike.

Sounds to me as you are blaming the pony instead of the inept diver. Someone that foolish, being nice here, should be taken back to school to learn about water safety and what it means to dive with another diver. What if you had an emergency? Is he going to hand you a water filled pony??

 

[caruso]

This is the exact reason I no longer allow pony bottles on my boat.

Who are you to decide what safety equipment a diver brings on your boat?

You're a taxi, nothing more. I'd walk right off the boat if anyone told me I couldn't dive with my pony.

You're wrong by the way, having the pony bottle is a true extra measure of safety. It provides more gas and a redundant breathing supply which will ALWAYS be safer than diving with a single tank.

 

[caruso]

Just bought a Pony....never dove with one. I assume I can fill it with Ean as well?

It's gotta be 02 clean and maintained to higher standards of cleanliness than a regular tank and you won't gain much by doing it if it's just a bailout/backup gas supply.

 

[flyboy08]

It's gotta be 02 clean and maintained to higher standards of cleanliness than a regular tank and you won't gain much by doing it if it's just a bailout/backup gas supply.

It’ll allow me to check our gear out in the pool before we partake any Dive trips....

 

[caruso]

It’ll allow me to check our gear out in the pool before we partake any Dive trips....

Don't need EAN for that.

 

[flyboy08]

Don't need EAN for that.

Obviously...if I took it on a Dive for redundancy, or a margin of safety for me....or anyone else that might experience an OOA situation it would have Ean. My wife Dives 21, but in an emergency, I doubt Ean would be turned down as it would be used to ascend, do a safety stop then surface.

 

[caruso]

Obviously...if I took it on a Dive for redundancy, or a margin of safety for me....or anyone else that might experience an OOA situation it would have Ean. My wife Dives 21, but in an emergency, I doubt Ean would be turned down as it would be used to ascend, do a safety stop then surface.

Don't need EAN for that.

 

[MaxBottomtime]

Who are you to decide what safety equipment a diver brings on your boat?

You're a taxi, nothing more. I'd walk right off the boat if anyone told me I couldn't dive with my pony.

You're wrong by the way, having the pony bottle is a true extra measure of safety. It provides more gas and a redundant breathing supply which will ALWAYS be safer than diving with a single tank.

I'm the Captain and owner of the boat. My boat, my rules. I've seen too many divers using a pony to extend dives and others not watching their SPGs knowing they have a pony to fall back on. I prefer to dive with those who don't allow themselves to get in a situation where a pony is needed.