list your pony bottle size options / reasons

[DetectorGuy]

Good conversation in this post. Someone should put together a list (or find a list online) of diver slang/acromyms/euphanisms. "pony bottle", "stage bottle", "bail-out bottle", "spare air", "EBS (Emergency Breathing Systems for Helicopter Evacuation)", "HEED (Helicopter Emergency Egress Device)", and the like... They are all congruent in that they are similar but different. I am still pretty green in the diving community, but "pony bottle" means different things to different people. I thought a pony bottle was just a redundant air source and not an additional air source to extend a dive. I thought the stage bottle was just that, a bottle of gas to breath on during a decompression dive on the ascent. I thought the spare air (EBS and HEED type) was just a placebo that gave a diver a false sense of security that in the event of an out of gas situation that the diver would be alright and everything would be rosey...  it doesnt matter if the glass is half full or half empty if your in the bottom of it with no air...