Pony bottle size

[divingdeputy]

as all the others have said it depends on the depth you are at. To tell you the truth i've been lucky enough to only have had to breath off it for more that a minute or two while training in a pool. Never had to use it in real life, just training. In a ten foot pool it lasted almost 30-45 minutes, but this was without the stress of being out of air or other gear failure. Any other time I've used it was just to practice and i only breathed off it for one or two minutes at a time. One thing I push with my team is if you are switching to a pony bottle its time to end the dive and get your butt to the surface, not continue the dive on the pony. Like i said earlier I do not do tech dives so I couldn't comment on a good size if you later plan to use it as a decon bottle. We do use a 30cf for a 15 foot hang tank on our deep dives but we are not going over the recreational depths or times.