Pony Bottles

[LKunze]

Anyone carry a pony tank on deeper dives when using a single tank rig? After witnessing Chris's and our instructor's freeflows a couple weeks ago on a 100 ft dive at Wazee, it made me wonder if a pony would be a good thing to start taking with me on my deeper dives (the instructor had a pony with on this dive BTW). Obviously proper gas management and utilizing the buddy system are the first solutions to handle OOA situations but in a catastrophic event such as two regulator freeflows or reg failures on the same dive make the pony seem to be a logical thing for single tank rigs. I've read many negative things about pony's and spare airs and I do feel spare airs are really a waste, and I'm just referring to the validity of pony bottles here. I can't see taking a pony on dives around here where you don't get deeper than 40 to 50 feet but for the deeper dives at Crosby, Wazee, Superior, etc. I'm wondering if it would be a good investment? Obviously a doubles rig would be ideal but that's not something I plan to get into anytime soon. Any thoughts?