Alright, I think I have settled on getting an al30 pony. I'm thinking DIN with an xtx50 on it. Am I overlooking anything or is there anything else I need to think about? I'm still not exactly sure how I'm going to rig it or how long a hose it should have.
Consider a 40 cu ft tank instead of the 30. They are the cylinder of choice for many tech divers, and it will serve you better if you consider going down the tech path in the future. May also have a better resale if you decide to sell later. A 40" hose will serve you well. There are commercial stage kits available or you can make one. Typically the top clip is clipped on a chest D ring and the bottom clip to the D ring on your waist strap. Just my $0.02.
I'm not planning to do any tech diving but I guess that doesn't mean I won't. I am just looking for redundancy because I don't trust instabuddies. I was considering a 19 and already thought I was overplanning with a 30.
I agree Matt, if you've got a decent breathing rate, and your not doing Tech, I've used a 30 for a couple decades now and its always been plenty of air. Terry
I agree with ChrisH on going with a 40 but nothing wrong with 30 if not doing tech diving in the future. Also, I agree on rigging it like a stage clipping it on your left side D-rings. One added plus to this method is that you can carry the tank down to the water and clip it on when you are in the water rather than on land. It's a little easier this way and you don't need to spend extra money and hassle with pony brackets etc.
I called one of the shops I've done some ordering from before and he suggested a rebreather valve on the pony. I looked it up and it does look like it could make for a more compact setup.
There are a lot of rebreather divers here, so any of you have thoughts on that?
OK, one more question. Is the swivel worth the extra money? I'm tempted to save the cash and buy the DS4 and not the DST.
Swivel not necessary really. I've owned both and prefer non-swivel first stages.
I had to think about this a second, but he just means a left hand valve? I would suggest figuring out how you are going to mount it before deciding on a valve. Presumably with the right and left valve, the knobs would both face out like a set of double so you could reach them. If you sling it like Lonnie and I recommended, you can easily reach and control the valve. Even if the regulator is freeflowing, you can turn the valve on and off to breathe from it. That would be tough with the tank behind you. In addition, if an instabuddy is having problems, you can pass the entire setup to them so they have gas to get to the surface. If you have the pony attached to a tank on your back not only is it less likely that you can reach the valve if there is a problem, but you can't pass it to another diver. Thinking about this more, I'm not sure an instabuddy would have a place to put a 40 if you handed it off...
OK,... Now I have a question related to "turning the pony tank on if or when you have a problem"... What are your thoughts on turning the pony tank on prior to the dive versus waiting to turn it on until you have a problem? I was told that if you have an older reg on the pony, and don't turn it on before the dive, that water can get forced through the mouthpiece, through the first stage, and into the second stage creating problems. I do fully like the idea of being able to reach the knob for a lot of reasons.
I am on the fence with the passing the pony/stage to a "instabuddy". The "instabuddy" probably was certified by the same agency (or agencies) as me or many of you. I don't remember in Openwater, Advanced Openwater, Rescue Diver, or Divermaster Certification anywhere that taught this skill... Did I miss that whole chapter? Would an "instabuddy" (who you may have just met that same day) be on board with learning this new skill set during the emergency situation? I agree that passing a stage has its place, but there are the standard practices for out of air situations that were taught to all of us that should do the trick.