Steel 72 as a pony?

[goodluck69]

Greetings,

Have an equipment realated question. I am currently diving with a 119cf and was looking at adding a pony bottle to my standard diving equipment for some of my deep dives (120-130'). After further thought, I have several 72's laying around and am curious about using them instead. My BC gives 45# lift, I regularly dive a 7mm farmer and run 18# of lead as my standard set-up. Can I sling a 72 with an independent set of regs, SPG and hose and loose some lead or do I need to have a technical rating to use this set-up?

 

[chrispete]

Here's the million dollar question. What happens if you have to hand off or drop the 72 and you've pulled that weight off of your belt?

 

[DennisW]

You don't have to have a technical rating to do anything. A ST 72 is a pretty big pony, but you surely would have plenty of air if you needed it. I think it would just be too darn heavy to carry along with your standard set up. If you need that much air, use doubles. Just my 2psi.

 

[MSilvia]

You don't have to have a technical rating to do it, but that doesn't make it a good idea. I wouldn't use a steel 72 that way myself, as I consider that excessively negative for a stage bottle. When I did my adv. nitrox class, I used steel 45s, and found them to be way too heavy for my taste. I felt like I was fighting against them for the entire dive. I was diving a drysuit for redundant buoyancy too. In a wetsuit, you're going to be increasingly negative as you go deeper, and if you have any sort of BC problem, you might have some difficulty in swimming up 2 steel tanks.

Aluminium 40s, by comparison, are hardly noticable. That's what I'd recommend.

 

[goodluck69]

Looking at it more as I have the equipment already to do this and money IS an issue. I actually have 2 119's and 6 steel 72's but insufficient funds to swap to a Transpac Dual RecWing and manifiold at this point, although it is in my master plan. I was only looking to capitalize on existing equipment.

 

[MSilvia]

No, no one will be checking your credentials to use a second tank, regardless of where you attach it. You might want to get some pointers from someone experienced in using one though.

 

[ClayJar]

Although I wouldn't want to sling anything as negative as a steel 72, you don't need any special card to dive slinging a tank. It would, of course, be a rather bad idea to sling it without trying it out on some easy dives, as I have a feeling it will have a considerable effect on your roll axis.

(I sling aluminum in the AL19 to AL80 range, myself, and I would certainly agree with anyone who says prior practice is prescribed when you're starting out on larger bottles. It wasn't "hard", but it wasn't exactly "normal" at first, either.)

 

[goodluck69]

No, no one will be checking your credentials to use a second tank, regardless of where you attach it. You might want to get some pointers from someone experienced in using one though.

Thanks for the info, I am not planning on jumping into this blindly. My LDS is a technical shop and I am sure would give me the same info. I hate to bring it up with them because SOME of them do believe there are such things a stupid question. I wanted to pose the question "anon" before running it up their pole.

I look at it this way, buying a second set of regs and SPG is not that big of a deal money wise. You can NEVER have too much air (unless there is a fire!). And I already have the tanks. Getting some time in the local quarry with an instructor to show me the ins and outs without killing myself...priceless...

 

[captain]

A steel 72 is only about 5 pounds negative full at 2500 and neutral to +1 empty. Other than the bulk I would think it is managable.

 

[goodluck69]

A steel 72 is only about 5 pounds negative full at 2500 and neutral to +1 empty. Other than the bulk I would think it is managable.

Love your quote...a man after my own heart...

"Never underestimate the power of a large group of stupid people."