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Made it just over a year and the paint had bubble, peeled etc (yes properly washed after every dive). Catalina replaced it, but with a non-painted one.....tells me they know there is an issue....told me "with your type of diving a non-painted one is better for you". Ocean diving...nothing really different. I have two 80CF Luxfers that are 4 years old with perfect paint.
You are confusing terms.
Which isn't surprising if you haven't pursued training yet.
A diver may sling a bottle (cylinder, tank, etc.) for different reasons, and the gas inside the bottle is planned for use differently for each separate reason. Defining terms helps prevent confusion.
While all the bottles are sling tanks, they can be --
* Bail out bottles - generally associated with rebreathers where failure may compromise the system. Bail out gas theoretically allows the diver to ascend safely. Solo divers also use these.
* Deco bottles have various gas mixes in them that the diver switches to at different points during the ascent, to ensure off-gassing occurs with maximum efficiency.
* Stage bottles are used at various points in a dive to extend the divers range (distance or time) for reasons that are specific to different types of diving. Stage bottles may either be slung on the diver or, for some diving (i.e. cave diving) may actually be "staged" on a line at various locations for future use.
While all the above are 'sling bottles', they serve different purposes and the gas inside them is planned for use in a variety of ways, depending on the dive.
One of the major flaws that some divers see with the use of pony bottles is that they are often used INSTEAD of gas planning, rather than AS A RESULT OF gas planning. Pony users occasionally adopt the attitude of "I don't need to do gas planning because I have a pony bottle - I'll just dive until I run out of gas and use my pony to ascend", or "who needs to plan their gas consumption? I've got my pony bottle - if I run low I'll just use it to ascend". Like everything else in life, its how you define terms that determines whether something is a helpful tool or an excuse.
And to address your key question above, the gas inside a 'pony bottle' is NOT planned for consumption during the dive. Assuming you're carrying the bottle to mitigate risk of some catastrophic failure at depth, it is a 'bail-out' bottle and contains the amount of gas you've calculated would be necessary to get you/and buddy to the surface from whatever depth and circumstances the dive entails. The bail-out gas is part of your gas plan, but as your contingency gas, not gas planned for use assuming all goes well.
Remember, though, that different divers define terms differently!Its always best to dive with a buddy, and to ensure you and your buddy create gas plans for your dives. Gas planning isn't difficult, and gas management can be critical to survival.
Dive safe,
Doc
