I dive with a full 19 cubic feet pony bottle and think is one of the best dive investments I’ve made. I conducted a 10’ pool dive and a 60’ spring dive test and found it’t plenty of air for any recreational dive I make within DECO limits. I find experience divers tend to think they’re close to each other, especially when the water is clear, but they’re not. Next time you dive test how long it takes you to get to your buddy on a breath of air...it’s a wake up call. I’m a pony bottle believer. See my Oriskany pic..you’ll see the bottle..I make the rigs for this type bottle.