doubles in DIR diving wet....

[cool_hardware52]

Be careful also of presuming that all steel tanks present weighting problems. The ones we use in Europe are almost neutral when empty so don't give the same problems. In comparison the 104s I wear in Florida leave me so negative with no weight at all that I can't get comfortable on the surface and have to wear extra undersuits to compensate.

You folks do have some interesting tanks "over there" funny sizes (Liters?, Bar? Kg?)

Not all the steel tanks sold in the US are massively negative. The PST104 certainly are "nuggets", but the faber LP 85's I use most of the time are neutral when empty. You might try a set of LP108's if you can get you hands on them. They are 8" dia, and are only ~-.5 kg empty, not -2~3kg like the 104's

Tobin

 

[ekewaka]

The point is that you need to analyze both posts.

I still don't understand why this is a problem. It only takes a few seconds to analyze both posts. Why do people have trouble doing that?

 

[limeyx]

What is this fascination with ditchable weight? I dive in caves. Ditchable weight is meaningless. It's meaningless for decompression diving as well. Last thing you want to do on a deco dive is LOSE ballast. Dive a balanced rig. Problem solved.

Well, if you can not swim up your full rig, then you have a problem in open water *or* in a cave.

If you can swim up the full Al80's or Lp85s with no gas in the wing from depth, then you dont need ditchable weight. But since you need to be negative at the start by the weight of your gas (15 pounds in AL80 ? 12 pounds ?) + enough to keep your wetsuit down at 10 feet, you might be 15-20 pounds negative -- not everyone can swim that up, so the solution to get a balanced rig is to make some weight ditchable.

if you dive the Lp85 and do not *need* and weight but cannot swim them up full, then you can not solve the problem to get a balanced rig. If you (as you do) need some weight with the AL80s then you can move it to a belt and ditch it if you absolutely have to (which is why people use Al80s over steel tanks when diving wet)

 

[JimC]

I still don't understand why this is a problem. It only takes a few seconds to analyze both posts. Why do people have trouble doing that?

Lazy, complacent, in a rush, have an LPI Adapter on the analyzer and don't dive a drysuit (only having 1 LPI hose) and unaware of need all come to mind right away. I am sure there are others.

 

[rjack321]

I still don't understand why this is a problem. It only takes a few seconds to analyze both posts. Why do people have trouble doing that?

I don't analyze both posts. But I fill all my own gas, in my own garage.

To really analyze both posts you need to close the isolator. Otherwise it draws gas from both sides and can mix in your reg and give who knows what reading. Probably not what you expected so you'd know something was amiss. But it may or may not have been that helpful in the Eagle's Nest incident.

If someone else fills my tanks I analyze both posts (rare).

But the OPs issue IMO is that he's taking doubles for "more gas" - more is better right? But having an issue underwater with doubles, that you don't understand their failure modes is not DIR. Take DIRF in doubles, learn how they work, pass/fail/provisional. Practice as an educated diver. That's the DIR approach to this.

 

[ekewaka]

Lazy, complacent, in a rush, have an LPI Adapter on the analyzer and don't dive a drysuit (only having 1 LPI hose) and unaware of need all come to mind right away. I am sure there are others.

Diving can be lots of fun, but it is a very serious and potentially dangerous activity. Laziness and complacency can get you killed.

 

[Jasonmh]

I...But the OPs issue IMO is that he's taking doubles for "more gas"

I don't think the OP said that he wants doubles for more gas. He said he wanted to try them out to get used to them because he is thinking about taking other tech classes, and later listed redundancy as another reason. Several times he said that he was going to stay within NDL and no deco diving.

To the OP:
As you can see, when you dig in to the issue it is not as simple as steel with wetsuit = bad in every occasion. From your original post, using a dual bladder wing is not considered DIR because it introduces unnesscary complications that came about by not using a balanced rig in the first place. I would say that double AL80s (not saying that is the only good answer) can be a good place for most people to start, because they are cheaper (a chance to try the doubles without spending a ton), easy to get, and (has been pointed out) can be broken down for something else in the future or back to singles if you decide that doubles aren't for you. But that's just my 2 cents.

 

[rjack321]

I agree, getting ready for another class is certainly valuable. Diving to 100ft with new stuff strapped to your back when you're not really sure how it works - that's beyond doubles orientation practice.

 

[JimC]

Laziness and complacency can get you killed.

Yes, it can. It is, however, quite common. There are lots and lots of people out there who never analyze ever. Not DIR, but it happens nonetheless.

 

[Icarusflies]

Jasonmh; The reason why I choose AL80's vs steel is balance/safety since I already have 2 HP 100's that I could double ($ not an issue just safety). Thank you for your input.