Steel HP 23 vs Al 19 redundant air source

[ChuckP]

Sometimes new divers get something in their head and put the blinders on....

You wanna back mount something - either one and I haven't dove either one but it matters not.

Why not to back mount it?

Less than 50 dives, a 23 or a 19 gives you no growth potential. Not being able to see what's in the tank is perfect up until the point what you think is in the tank ain't. All the cutting tools in the world doesn't make it OK to increase your entanglement odds, especially when diving solo. A mounted cylinder is just odd - odd to carry it, odd to fasten and unfasten, odd filling your main tank - it's just odd.

A slung bottle just has soo many advantages verses mounted, but sometimes the blinders block the view.

 

[Cdncoldwater]

Sometimes new divers get something in their head and put the blinders on....

You wanna back mount something - either one and I haven't dove either one but it matters not.

Why not to back mount it?

Less than 50 dives, a 23 or a 19 gives you no growth potential. Not being able to see what's in the tank is perfect up until the point what you think is in the tank ain't. All the cutting tools in the world doesn't make it OK to increase your entanglement odds, especially when diving solo. A mounted cylinder is just odd - odd to carry it, odd to fasten and unfasten, odd filling your main tank - it's just odd.

A slung bottle just has soo many advantages verses mounted, but sometimes the blinders block the view.

Just a quick question, if it is such a hazard why is it common in the PSD realm to have a pony on your back mount? I would agree that these are a bit small as far as capacity.

 

[Cdncoldwater]

People have actually died with backmounted ponies. They apparently thought they were on their main tank, but were on pony and drowned when they ran out of air in pony tank. Pony reg was apparently on necklace. Slung pony with second stage that is bungeed to the pony means there is a lot less confusion between back gas and pony.

It would appear that the casualty(s) of this scenario didn't know their equipment/ set up and that is a critical factor to solo diving. Simply having a different colour mouth piece could identify the pony regulator to minimize the use of the wrong one. I would also ask why they didn't switch regulators and were they trained/experienced with their set up?

 

[RyanT]

al30 would be better for a variety of reasons:
takes a standard stage kit and is easy to sling
removable in case of entanglement
easy to donate gas to someone on the 40" hose
easy to check pressure on a 6" spg hose
30% more gas
convertible to an o2 deco bottle in the future

Not a fan of upside down pony bottles hard mounted to your main tank

Agree with this on all accounts. The bottle mounted on your primary tank will tend to roll you. Sure you can counterbalance with additional weight on the opposite side, but it still won't ride as comfortably as a slung bottle.

People have actually died with backmounted ponies. They apparently thought they were on their main tank, but were on pony and drowned when they ran out of air in pony tank. Pony reg was apparently on necklace. Slung pony with second stage that is bungeed to the pony means there is a lot less confusion between back gas and pony.

Nope, Marie is not kidding about this. It might seem unbelievable when you are sitting on your couch thinking about it. Underwater and under duress is a whole different ballgame.

Less than 50 dives, a 23 or a 19 gives you no growth potential. Not being able to see what's in the tank is perfect up until the point what you think is in the tank ain't. All the cutting tools in the world doesn't make it OK to increase your entanglement odds, especially when diving solo. A mounted cylinder is just odd - odd to carry it, odd to fasten and unfasten, odd filling your main tank - it's just odd.

A slung bottle just has soo many advantages verses mounted, but sometimes the blinders block the view.

And this.^. You've gotten some really good advice here in this thread. Good luck with your setup.

 

[KenGordon]

This seems unbelievable really. Whether the tank is slung or mounted is irrelevant. There are two regulators and two air sources. If one doesn't work, you use the other.

You have a main tank and regulator, you have a pony bottle and regulator. You put the main in your mouth and the pony is there for emergency.

If someone drowns because they drained their pony bottle, then they should have been prepared to switch over to their main tank, which would have been on from the start. If you are out of air, you switch tanks. It's why you have two tanks. No need to drown at all.

I'm simply asking for advice on which tank to use. If you haven't used either, just keep reading and don't respond. If you have experience with either or both, please let me know what you think of their performance.

You are making a normal mistake of assuming that people manage to do the best thing in adverse circumstances. Sometimes they don’t and they die. It is a risk. If you cannot see that it is a risk and imagine you could make such a mistake you are missing out on learning from the mistakes others have made at great cost.

I dislike ponies as they are generally too small but have been using one the past few weeks as for practical reasons I had to dive a single and had no idea who my buddies would be or whether I would be solo. Deepest was 28m so more or less ok.

if you have to carry any lead at all then I suggest a steel. An ali will be more comfortable but then you might as well get a 40 and not be worried about how big it is.

The steel will tend to roll you so move a kilo from left to right. You quickly get used to it.

I had my pony slung just like any stage/deco cylinder. This made handing it up to the boat easier, shore entries/exits easier and generally moving stuff to and from the boat easier. It also means that you can be much more sure about which cylinder you are breathing off.

You may think that you can always tell one reg from another but you cannot be certain of that. All sorts of stuff can intervene and add confusion. Say your pony reg dies or gets left at home and you have borrow one that looks like your main?

you might think “but if I check my SPG and it has not gone down I will know”. I have done a whole twinset dive with the isolator closed and not noticed the SPG never move. We all
make mistakes, try to arrange stuff so that the mistakes don’t always kill you.

 

[KenGordon]

It would appear that the casualty(s) of this scenario didn't know their equipment/ set up and that is a critical factor to solo diving. Simply having a different colour mouth piece could identify the pony regulator to minimize the use of the wrong one. I would also ask why they didn't switch regulators and were they trained/experienced with their set up?

We can’t ask them, they are dead. But we can acknowledge the risk, imagine they didn’t leave the house thinking “a good day to die in a particularly needless fashion” and take note that it happened.

Everyone is inexperienced to begin with, although often it is the experienced that make the most silly mistakes once they become complacent.

 

[apenland01]

Responses appreciated.

@Marie13 I wasn't trying to be rude or snarky in my response, so please don't take it that way.

 

[drk5036]

I think it’s hard to often understand the amount of air in these cylinders. To put it in context, a good way to think about it is a 19 cf cylinder is about equivalent to a regular Al80 at 50 bar. If you’re at depth with that much air, how do you feel? That’s one good way to gauge how much air you need.

 

[apenland01]

As for the size of the bottle, a 19 or 23 would suffice for what I need it do. I need it to provide redundant air on dives around 60 feet or less in case of equipment failure of some sort. A 30 or 40 simply seems like overkill for this use. I probably do have the blinders on, since I'm an older diver with no plans to do any tech diving or deco diving ever in the future. I don't go the ocean often, so there's a lot of things that don't come into play for me personally.

I've never been diving with a slung bottle and only used a backmounted pony a few times years ago. It was held to the main tank by an adapter and cam band. It wasn't difficult to manage and I don't recall it being horribly out of balance in the water, but it was years ago.

When I first started looking around, I had considered a 6cf Spare Air and decided that wasn't enough air to get myself out of trouble and I decided to get a smaller pony bottle that has it's own dedicated regulator, which is the same as my primary, but different color and different color hose.

again, I appreciate the responses.

 

[Marie13]

You might also consider resale valve. Especially since you’re an “older diver” as you call yourself. Resale value on a 40 is going to be much better.