Pony Bottle pros & Cons

[O-ring]

On your first dive, you have plenty of gas to get things shut down and still get to the surface at a leisurely pace. However it seems that almost everyone that dives doubles, does two dives on a set.

So how is doing two dives on a set of 100 cuft doubles safer than doing two dives with 100 cuft tanks, switching the tanks in between, while still having the bail out bottle for insurance on both dives? A full single 100 cuft tank + a pony bottle seems to me to be a safer option than the second dive on a set of doubled 100s.

So I'm obviously missing something... what is it I'm missing?

...my buddies and I are slowly moving toward the doubles route as well. We are going to do double AL80s and carry an AL80 stage. The way we figure it, that gives us as much gas or more than someone diving two AL100 singles or two ST125 singles. We were planning on doing dive 1 on the stage and some of the backgas and then doing dive 2 without the stage and just breathing off the doubles. If you wanted more bailout options on dive 2, just carry another stage or leave enough for bailout and switch back to the backgas. At least this is what we are planning to do...

 

[Dectek]

You all left out another point about the pony.
You can stand there and argue until you are blue in the face.....but if the boat captain tells you that you don't get on his boat unless you have a pony bottle.......you either produce one or fly back to Indiana. Most of the charter boats in this area require pony bottles.

 

[O-ring]

You all left out another point about the pony.
You can stand there and argue until you are blue in the face.....but if the boat captain tells you that you don't get on his boat unless you have a pony bottle.......you either produce one or fly back to Indiana. Most of the charter boats in this area require pony bottles.

Won't they accept manifolded doubles with an isolator valve instead?

 

[Uncle Pug]

Dectek once bubbled...
You all left out another point about the pony.

Don't go.
I don't let no stinking *boat captain* tell me what, how and when to dive....
Of course I'm usually the captain... but on the charters I have been on out here in the PNW there was never a hint of that...

Which brings up another point.... if the charter boats in your area treat you like little children who need to be told what to do... perhaps you should move to the PNW where the diving is better anyway

Yes I'm grumpy... I haven't had my latte yet.

 

[Spectre]

Dectek once bubbled...
but if the boat captain tells you that you don't get on his boat unless you have a pony bottle.......

I've not found, nor heard of, a boat that requires a Pony Bottle. They've required redundancy, but not a pony bottle specifically. doubles with isolation valves are fine [not sure about singles with h-valves, but that's not much different than a small set of doubles].

 

[Dectek]

Did some asking and was told that a pony or "INDEPENDANT ALTERNATE AIR SOURCE" was required. I do see your point that a manifold with Isolator valve is redudant however it is in the gray area of Independant. Independant to me means totally seperate with no dependant parts (tank and manifold). When push comes to shove the captain would probably allow the doubles to go. He did some back peddling and said that you OR your buddy had to have an independant air source.
I also did some reading of webpages of some dive boats in the area and found that several say that a pony is required and then in another area explain that it is on certain dives.

I go on record to making a statement that may not be 100% accurate. And while at it......apologize for really bad spelling.