Info Published Standards for SSI, SDI, and PADI "solo" courses

[CWK]

Calculating requirements for a pony is always interesting. I think of it in a way that is not taught in classes. I think of my pony in terms of buddy equivalents.

In buddy diving, your buddy carries your redundant air in his one and only tank. This means each gets 50% of whatever air is in the tank. If you dive with a Al40 as your pony, it’s equivalent to diving with a buddy who always has a full Al80. So I think a Al40 is excessive.

 

[Robert H. Diver]

Calculating requirements for a pony is always interesting. I think of it in a way that is not taught in classes. I think of my pony in terms of buddy equivalents.

In buddy diving, your buddy carries your redundant air in his one and only tank. This means each gets 50% of whatever air is in the tank. If you dive with a Al40 as your pony, it’s equivalent to diving with a buddy who always has a full Al80. So I think a Al40 is excessive.

No one ever died from too much gas. AL 40’s are small, and if clipped off/bungeed properly you don’t even know they’re there.

 

[boulderjohn]

and if clipped off/bungeed properly you don’t even know they’re there.

A certain tech instructor I know got an idea from the head of his agency for a trick he used in his training. He would get students involved in a task, come up behind them, and quietly unclip an AL 40 deco bottle. He would then take the bottle while the student was engaged in the task. When the student was done, he would signal the start of a simulated deco ascent, at which point the student would discover that his deco bottle had disappeared. No one ever caught on before then.

Note that I am not advocating this as a part of training. It is a stupid practice that serves no purpose. It does, however, illustrate the point that you won't even know the AL 40 is there once you are used to it.

 

[Robert H. Diver]

A certain tech instructor I know got an idea from the head of his agency for a trick he used in his training. He would get students involved in a task, come up behind them, and quietly unclip an AL 40 deco bottle. He would then take the bottle while the student was engaged in the task. When the student was done, he would signal the start of a simulated deco ascent, at which point the student would discover that his deco bottle had disappeared. No one ever caught on before then.

Note that I am not advocating this as a part of training. It is a stupid practice that serves no purpose. It does, however, illustrate the point that you won't even know the AL 40 is there once you are used to it.

Exactly. I barely know my LP 85’s are there when I dive sidemount unless I’m fiddling with a valve or in a weird position.

 

[CWK]

No one ever died from too much gas. AL 40’s are small, and if clipped off/bungeed properly you don’t even know they’re there.

I agree that no one has ever died from carrying too much gas. Certainly no one has ever died from being overly conservative.

I lug a pony all around the world and I go on a dive trip somewhere every month. So I do question how conservative I want to be because I have to pay for my excess baggage.

From memory, I believe that my Al19 plus reg weighs about 5kg. It also has a buddy equivalent of a buddy with 95 bar in an Al80, which I think is more than sufficient to get me to the surface from 40m. Should I get an Al40 pony? I think not. That is just my personal opinion.

 

[tursiops]

I allowed the use of any size cylinder, as long as it was a completely redundant air cylinder.

That is my desire too. But SDI allows H-valves. At least PADI is clear on that.

I agree that no one has ever died from carrying too much gas. Certainly no one has ever died from being overly conservative.

I lug a pony all around the world and I go on a dive trip somewhere every month. So I do question how conservative I want to be because I have to pay for my excess baggage.

From memory, I believe that my Al19 plus reg weighs about 5kg. It also has a buddy equivalent of a buddy with 95 bar in an Al80, which I think is more than sufficient to get me to the surface from 40m. Should I get an Al40 pony? I think not. That is just my personal opinion.

One consideration is what other kinds of diving does one do, how do they ravel, and do they expect to rent or own their tanks. The AL19 is the largest reasonable traveling-by-air tank. It is rarely used for any deco diving. AL 40s are multipurpose, being more than adequate for recreational solo diving, as you point out, but also are very common as deco bottles for tech diving, holding 50% O2, 80% 100%, whatever is appropriate. They often can be rented from the dive operator; AL 19 sometimes.

 

[Robert H. Diver]

I agree that no one has ever died from carrying too much gas. Certainly no one has ever died from being overly conservative.

I lug a pony all around the world and I go on a dive trip somewhere every month. So I do question how conservative I want to be because I have to pay for my excess baggage.

From memory, I believe that my Al19 plus reg weighs about 5kg. It also has a buddy equivalent of a buddy with 95 bar in an Al80, which I think is more than sufficient to get me to the surface from 40m. Should I get an Al40 pony? I think not. That is just my personal opinion.

Traveling with a pony is a completely different story…

 

[Wookie]

That is my desire too. But SDI allows H-valves. At least PADI is clear on that.

Yes, SDI allows H or Y valves, and I allowed them on the spree, but if you were taking the class from me, I exceeded standards.

 

[neeka]

I would be interested in finding a solo manual for reference purposes and entertainment.

just wondering if there is an SDI shop near Kansas City. I can think of two dive shops that are nearby, one is PADI, the other I'm not sure. will do some research on the subject and see if the situation warrants more questions.

 

[tursiops]

I would be interested in finding a solo manual for reference purposes and entertainment.

Buy one from SDI.