Colliam7:
I find the 19cf a perfect size those 'sportier' rec dives.
Pony orientation debate?
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I find the 19cf a perfect size those 'sportier' rec dives.
Diveral
Contributor
There's lots of different opinions of sizes and mounting options expressed here and they are all mostly correct for the diving they do. So the questions really boils down to: What are you expecting the pony to do for you? What kind of diving will you be doing while you are wearing it? Are you willing to carry the size you have selected? and is it big enough for what you want it to do?
You need to know what your SCR is. I've got mine and have set up a spreadsheet for different depths and tank sizes so I can model my dive profiles to determine how much time a certain tank size will give me at a specified depth. I then select the size off of how much time I'm going to need. The higher your SCR the bigger the tank you will need. The deeper you dive again the bigger the pony you will need.
Are you going to be diving in overheads? Again if yes then you will need a larger pony.
Do you get lost much and need to spend time finding your ascent point? If yes then you need a larger pony.
Do you tend to become distracted and go OOA often? If so how far do you need to swim to reach your ascent point? This is a loaded question and I'm not going to delve into it.
So for me and my typical diving profiles here are the answers:
A 6 cu ft will allow me to ascend from 120 feet on a recreational profile. If I'm below 90 feet the ascent begins immediately straight up and its 60 ft/min until I hit 30 feet and I go to 30 feet/min with about a 1.5 min stop at 15 feet. If I'm at 90' or above its 60 ft/min to 60 feet. if the ascent point is in sight I will angle up to it. At 60 feet I go to my normal ascent profile.
A 13 cu ft will allow me to execute a normal ascent profile from just about any recreational depth I can imagine. Can't spend much time as a lost diver though.
19 cu ft is the one I use for most of my limited penetration diving. I mount it to my tank. It gives me about 6 minutes of air at 100 feet. So for any type of penetration diving it is marginal at depths exceeding 100 feet or deeper linear penetrations.
For those I use a slung 45 which gives me 15 minutes at 100 feet. A 30 would work as well but I don't have one of those.
So I guess the answer to your question is it depends.
Buy the pony to match the profile of the dive you want it to. You may need more than one.
For me I'd buy one of those 6 cu ft H2O Odysseys for travel diving to tropical locations if I wanted redundant air. Put it in your check on baggage. For most of my deeper & wreck/cavern dives a 19 is suitable. Then there are those dives where I cross over into the lite tech side and the 45 is needed.
AL
You need to know what your SCR is. I've got mine and have set up a spreadsheet for different depths and tank sizes so I can model my dive profiles to determine how much time a certain tank size will give me at a specified depth. I then select the size off of how much time I'm going to need. The higher your SCR the bigger the tank you will need. The deeper you dive again the bigger the pony you will need.
Are you going to be diving in overheads? Again if yes then you will need a larger pony.
Do you get lost much and need to spend time finding your ascent point? If yes then you need a larger pony.
Do you tend to become distracted and go OOA often? If so how far do you need to swim to reach your ascent point? This is a loaded question and I'm not going to delve into it.
So for me and my typical diving profiles here are the answers:
A 6 cu ft will allow me to ascend from 120 feet on a recreational profile. If I'm below 90 feet the ascent begins immediately straight up and its 60 ft/min until I hit 30 feet and I go to 30 feet/min with about a 1.5 min stop at 15 feet. If I'm at 90' or above its 60 ft/min to 60 feet. if the ascent point is in sight I will angle up to it. At 60 feet I go to my normal ascent profile.
A 13 cu ft will allow me to execute a normal ascent profile from just about any recreational depth I can imagine. Can't spend much time as a lost diver though.
19 cu ft is the one I use for most of my limited penetration diving. I mount it to my tank. It gives me about 6 minutes of air at 100 feet. So for any type of penetration diving it is marginal at depths exceeding 100 feet or deeper linear penetrations.
For those I use a slung 45 which gives me 15 minutes at 100 feet. A 30 would work as well but I don't have one of those.
So I guess the answer to your question is it depends.
Buy the pony to match the profile of the dive you want it to. You may need more than one. For me I'd buy one of those 6 cu ft H2O Odysseys for travel diving to tropical locations if I wanted redundant air. Put it in your check on baggage. For most of my deeper & wreck/cavern dives a 19 is suitable. Then there are those dives where I cross over into the lite tech side and the 45 is needed.
AL
I nearly said that I tie a compass to my pony's mane and tell him what day it is before realizing this wasn't an April fool post...
lamont
Contributor
Diveral:
I wouldn't use less than a 19 cu ft tank on a recreational profile to 100 fsw:
http://www.scriptkiddie.org/diving/rockbottom.html#tables
And if you are doing wreck penetration, you should be diving doubles, running a reel and should have way more gas reserve than 6 mins at 100 fsw.
This is an example of how poking your head into a room for 5 minutes which has an immediate exit can result in being lost for 30 mins in a siltout inside of the wreck:
http://drmike.smugmug.com/gallery/1636631#79880032
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If your diving a single tank lets say a 130 and we are going to dive a shallow wreck say at 65 ft. The pony ( never used one less than 40 cu ft ) used for a redundant air source: my 2 cents right side of the main tank, valve up and canister light battery left side.
But with doubles? Carrying a pony? Ahhh - no. A swing tank at least 80 up.
Before I seen with doubles I voted Right side valve up. The reason why stated above.
If I'm hanging there doing DECO not on a single and not with a pony! There's something about hanging on a deco stop with 130's on your back and single side 130 are 2 swing mounts with deco gas what ever. You know whats cooler even DECO tanks hanging on a trapeze, each with 2 to 3, - 2nd stages hanging there!
But with doubles? Carrying a pony? Ahhh - no. A swing tank at least 80 up.
Before I seen with doubles I voted Right side valve up. The reason why stated above.
If I'm hanging there doing DECO not on a single and not with a pony! There's something about hanging on a deco stop with 130's on your back and single side 130 are 2 swing mounts with deco gas what ever. You know whats cooler even DECO tanks hanging on a trapeze, each with 2 to 3, - 2nd stages hanging there!
Diveral
Contributor
Just re-read the OP's first post. He's gone into tech and deco diving. My reply is more geared towards rec diving except for the 45 cu ft deco bottle of course. If you are into tech rec penetrations Lamont's and others replies are far better advice.
I dive rule of thirds, the 19 cu ft tank is just in case I have an equipment failure. When I am diving with it, I'm in Cavern mode and never out of the light zone. And yes I do consider silt-outs.
I dive rule of thirds, the 19 cu ft tank is just in case I have an equipment failure. When I am diving with it, I'm in Cavern mode and never out of the light zone. And yes I do consider silt-outs.
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The good news about that 6cf is that when you eventually realize how useless it is - it can easily be converted to an argon bottle. Same with a 13cf.
The worst choice is a 19cf. Too big for argon, still too small to actually breath from.
30cf makes a good O2 bottle, 40cf are needed for 50%. Use doubles for redundancy.
The worst choice is a 19cf. Too big for argon, still too small to actually breath from.
30cf makes a good O2 bottle, 40cf are needed for 50%. Use doubles for redundancy.
billyh
Guest
lamont:
What an interesting story. I am glad the diver made it out alive and kicking. But it begs the question: a $10,000 rebreather, high-zoot scooter, plenty of stages and other toys, but won't use a penetration line because. . .??? What an excellent shortcut to the cluster *******, IMO.
Normally, I will sling my pony/stage on my left side.
BUT... I have 1 exception to that method.
When I am filming, the staged bottle gets in the way of my freedom of movement while handling my camera gear. Therefore I prefer a 23cf steel pony mounted to my single 120 with the reg on a lanyard. Some places I go, I cannot lug doubles, therefore a pony is my choice for redundancy. Mind you, I use this method only in Open Water, and never below 100 ft. Anything deeper, longer, or overhead, and it's doubles.
Cheers
Mike
BUT... I have 1 exception to that method.
When I am filming, the staged bottle gets in the way of my freedom of movement while handling my camera gear. Therefore I prefer a 23cf steel pony mounted to my single 120 with the reg on a lanyard. Some places I go, I cannot lug doubles, therefore a pony is my choice for redundancy. Mind you, I use this method only in Open Water, and never below 100 ft. Anything deeper, longer, or overhead, and it's doubles.
Cheers
Mike
Wherever they will fit, but otherwise on the LHS
Cheers
Chriso
Cheers
Chriso
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