Why Steel Doubles?

[elan]

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.

it's a kind of strange to put the criteria on how comfortable you can don/doff your rig in front of the line while selecting the type of the tanks, do not you find ?

 

[ligersandtions]

Why is doffing and donning underwater part of your criteria? I don't get it....I've never been in a situation where I thought taking my rig off would help more than just asking my buddy to help me out with whatever (entanglement is the only thing I've run into, and even that would have been easy enough for me to free myself without my buddy....though it was nice that she had already seen the issue and was helping me free myself before I even really noticed).

FWIW, with steel doubles, I still used some weight on my belt (without being overweighted). Diving in socal, I assume my undergarments were thinner (and thus less buoyant) than what you're diving. However, if you're diving wet....steel doubles is probably not your best bet anyways.

 

[Rainer]

However, if you're diving wet....steel doubles is probably not your best bet anyways.

LOL, if he's diving wet in WA, he has bigger problems that choosing AL or steel doubles!

And yeah, I simply don't get this whole "take the rig off" in the water thing. I can't imagine wanting or needing to do that.

 

[WD8CDH]

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

Probably because it is next to imposible to find a non-isolator manifold at a US LDS. Non-isolator manifolds are quite common and easy to find in Europe.

 

[Dive0saur]

Again to clarify, I always dive with a buddy and am a firm believer in diving as a team, but I also am a firm believer that should the situation arise a diver should be able to solve issues of his own on his own. So primarily a don and doff would be a skill that might be one's best choice in a entanglement situation.

And yes I do acknowledge that most divers do require additional ballast besides steel tanks, but the point is that you still require the weight from the scuba unit to keep yourself orientated in the water.

 

[Kern]

And yes I do acknowledge that most divers do require additional ballast besides steel tanks, but the point is that you still require the weight from the scuba unit to keep yourself orientated in the water.

I'v not actually done it, but I feel reasonably confident that I could adjust the size & position of the bubble in my DS to maintain any trim required.

 

[StreetDoctor]

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

Now he's a comedian! You asked a question on a public message forum and I answered with my opinion (an opinion obviously shared by others), if you don't like it too bad.

How about this answer: You're right everyone and else is wrong, it's impossible. You're a PADI MASTER SCUBA DIVER TRAINER and you didn't know this? If you dive steel doubles apparently you WILL DIE. So stick to your aluminum tanks and have fun doffing/donning as many times as you like. Meanwhile, if I get in a jam in my double 130's I'll rely on my team to help me out.

 

[elan]

I'v not actually done it, but I feel reasonably confident that I could adjust the size & position of the bubble in my DS to maintain any trim required.

Well the bubble by itself will not help as the whole dry suit will be positive if you carry all the weight on the rig. so basically the trim will be determined by which point of the body is connected to the rig. So if you just hold on to your rig with your hands your body will be finding the position above the point of connection to the rig. if you just relax you arm holding to the rig you will end up feet up.

 

[Kern]

Well the bubble by itself will not help as the whole dry suit will be positive if you carry all the weight on the rig. so basically the trim will be determined by which point of the body is connected to the rig. So if you just hold on to your rig with your hands your body will be finding the position above the point of connection to the rig. if you just relax you arm holding to the rig you will end up feet up.

As I said earlier, I'm positive with empty tanks. As a consequence, I wear a weight belt. With a little adjustment to the bubble I think I may be able to hold trim & position in the water column without holding onto anything.

 

[StreetDoctor]

As I said earlier, I'm positive with empty tanks. As a consequence, I wear a weight belt.

Even though you're positive with empty tanks your tanks are still negative by themselves, you just wear a weight belt to make yourself more negative. All your weight is neither on the tanks or on you therefore if you seperate yourself from the tanks you will indeed still be positive. Let's break it down using 130s as an example:

130's - -2lbs each empty
regs- -4
BP AL or SS (-2 to -6)
Bands/manifold -5
Can light -3

That makes -18 to -22 depending on what your plate is made of.

Personally my undergarmets are 25lbs positive in the drysuit alone. I wear an additional 4lbs in a tailweight to remain neutral at the end of the dive. Does this make sense?

Edit:

I'm sure you know this, I'm at work and I'm tired and I think I read the previous couple posts wrong. Sorry if this is useless, hopefully it'll at least help someone else