Why Steel Doubles?

[Leadking]

DiveOsaur,

what rig are you diving? Almost all tanks are now mounted to the BC. You should be able to inflate the BC to neutral.

By the way I dove double al 80's in the 70's moved to steel doubles in the 90's and now do a rebreather. The one thing I learned is; it is only a question of where do you want to wear your weight. On your back or on your waist? Being able to ditch your lead and becoming positive is a point lost on most of this group. I am aware of many fatalities because of this quirk.

 

[Dive0saur]

It's difficult to say when you will need this skill, but that's why as divers we practice and prepare for the worst, right? If there was no need to do so why dive with an isolator valve on your manifold?

 

[HowardE]

If there was no need to do so why dive with an isolator valve on your manifold?

Not everyone does.

 

[elan]

Besides things such as trim and how well you can handle heavy tanks have to be taken into account.
Some folks here dive double AL80 just because they trim well with them. I was doing some trials and looking through the characteristics and HP100 I found to be very marginal length wise for me (I have to put them all the way down). Another one would be HP120 (that would probably be my next set) and LP85. That was it.

I do not want to kill my back with monsters like LP108 and HP130.

 

[Dive0saur]

To reiterate, I posted this thread to mainly see if anyone could combat the fact that while a diver depends on his scuba unit for weighting he will have a difficult time preforming a don and doff.

 

[StreetDoctor]

I don't ever plan on taking my doubles off under water. Hopefully my team is able to tell whether or not a potential problem is fixable, take the necessary steps and call the dive. Just like I don't ever plan on ditching a weight belt (if I wore one) on the bottom. So I guess your question is invalid for me? BTW I also dive double 130's and still wear 4lbs of lead and no I'm not overweighted. The 4lbs is in a DSS tail weight on the bottom bolt and trims me out perfectly.

 

[Dive0saur]

StreetDoctor, Finally an answer that is relevant. I appreciate it. I wonder how many people feel the same way?

 

[Rainer]

great points, but I myself am completely neg when giving steel doubles and any additional weight would cause drag =(

You're negative with empty steel doubles and no additional weight (diving in WA)? With a SS backplate or AL? Even with a SS plate and steel doubles, I'm positive (dry suit, 300-400g undergarments).

 

[Kern]

You're negative with empty steel doubles and no additional weight (diving in WA)? With a SS backplate or AL? Even with a SS plate and steel doubles, I'm positive (dry suit, 300-400g undergarments).

I was wondering about that too. With empty tanks I'm positive. I dive SS BP & 12lt x 232bar (100 cft) steel doubles, dry with 200g undies.

 

[Doc Harry]

Almost no one who dives doubles ever has any intent of removing their kit underwater.

A few cave and wreck divers might find them selves in a situation where they need to remove their cylinders to get through a tight spot. But removing cylinders in these situations is not a spur-of-the-moment thing, it is planned. They will either go home and switch to side mount, or go home and plan how they intend to return and push their cylinders through a restriction.

Solo divers need to be able remove their kit underwater in case the situation arises when the need to disentangle themselves.