Weight Systems - DIR point of view

[AndrewJD]

Aluminum vs. Steel

 

[Wreck Junkie]

Hey...thank you all for your valuable suggestions even though it has veered more on Als vs Steel!! Swimming up with the twin steels doesn't seem to be a problem as its a drill i do every now and then. Should i suffer cramps or physical exhaution, a lift bag will assist. Finally...my buddy...

The weight belt still seems to be the best option for a number of reasons that suit my rigging, just as long as its DIR. Plus, dof/donning the kit underwater on solid "ground" shouldn't prove that hard unless there are problems with the wing. I think that by simply inflating the wing to a slighty positive buoyant status should do the job without risking uncontrolled ascent. That could be a solution to "Mindgrabber's" apprehensiveness to removing the kit with steel tanks.

Have a great fes'd'ive season.

 

[mindGrabber]

I'll just accept the fact that I can swim my double 130s up in the ocean and that a *complete* drysuit AND *complete* wing failure is about as likely as pigs flying.

I don't believe that pigs can fly

I told nothing about *complete* wings failure. I told about catastrophic gas loss and I told that AL doubles rig is more balanced than steel doubles rig.

It means that if you are diving steel doubles rig (*less* balanced) in a case of catastrophic gas loss it will require you to manage your buoyancy somehow. Inflate you wings orally? Take your buddy’s hose to inflate your dry-suit? Anyway it’s additional task for you to manage in a stress situation when you are already managing a couple of emergency tasks.

My point is that diving AL tanks in a case of emergency situation simply cuts down a number of tasks to manage (which is very important due to you are under the stress).

That’s why I think diving AL tanks in blue water is safer.

 

[Soggy]

I told nothing about *complete* wings failure. I told about catastrophic gas loss and I told that AL doubles rig is more balanced than steel doubles rig.

This doesn't make any sense. How does having catastrophic gas loss affect the situation? We weight ourselves so we are neutral with empty tanks. Steel or aluminum, we'll still be neutral with empty tanks...if not, moving up a few feet in the water column will allow the gas in our wing/suit to expand, thus providing us with additional buoyancy without need for orally inflating the wing.

Even if you did have a catastrophic gas loss....orally inflating the wing isn't a big deal. For me, aluminum doubles would be *less* balanced, as the inherent positive buoyancy of the tanks would require me to wear a substantial amount of lead to keep myself neutral with empty tanks.

This particular argument really doesn't make any sense. Was it taught by your Tech 1 instructor or just something you came up with yourself?

 

[mindGrabber]

Was it taught by your Tech 1 instructor or just something you came up with yourself?

I didn’t discuss that topic with my gue instructor. So my point on that topic is something I came up by myself basing on idea that AL tanks buoyancy easer to manage. So I’m gonna use AL tanks with both wet and dry suit in sea environment always when it’s possible.

 

[Dryglove]

I didn’t discuss that topic with my gue instructor. So my point on that topic is something I came up by myself basing on idea that AL tanks buoyancy easer to manage. So I’m gonna use AL tanks with both wet and dry suit in sea environment always when it’s possible.

Read this excellent post by spectre in another thread a while back on the same subject http://www.scubaboard.com/showthread.php?t=77558&page=9&pp=10&highlight=steel


"First up.. a qualifying test:

Step 1: drain your tanks to empty. Take out the bladder in your wing [no cheating!]. Go out to 130 ft of water. Gear up, jump in.

Step 2, if you are still alive: swap your empty tanks out with full tanks. Take your lift bags/smbs/etc out and leave them on the deck. Jump in.

Now.... If you don't have that level of confidence that you've got your setup right, then you really have no business debating the issue. And I don't mean for anyone to answer.... Just think about that and be -perfectly- honest with yourself.

Now. Let's talk about "Don't dive steels wet". This isn't a rule of thumb, this isn't a blanket statement... this is a tagline to denote a concept. The -concept- being more crucial than the tagline now in the world of lighter steel tanks and heavier aluminum tanks.

First up. warm water aluminum vs. steel. Get your steel doubles on, put on your 3mm, proceed to Litmus Test Step #1 as described above. If you are still alive, you either are underweighted, or you've completely missed the boat on the whole fitness concept [e.g. you qualify as a HFS].

THAT is the core base of the concept... people actually being overweighted to begin with.

NOW. For those of you that picked up -that- part of the message, and have passed Litmus Test Step #1.

Next up is step #2. We're going to the other end of the extreme for this one.... cold water wetsuits; since this is the tough concept. IF you pass step #1, and you are doing step #2... what is the difference between sitting at 130 feet with steels on, vs. sitting at 130 feet with aluminum tanks on?

NOTHING! Zilch. Zero. NADA.

Oh but you disagree. 77.4 * 3000 psi blah blah blah blah blah. YES. The difference between double 104s and double 80s is about 4 lbs of gas.

If you can't swim that extra 4 lbs... FREEFLOW IT OUT!

Now... All those that are convinced you will survive Step #2 with your double aluminums, are you comfortable enough to try Step #2 with double 104s?

If you aren't... you've been talking out your ***.

NEXT UP. DITCHABLE WEIGHT! Here's the biggest rub I have with all the damn steel vs. aluminum debates. If you need 11 lbs to get down and you do that with a double 104s and a 5 lb plate, or you do that with double AL80s, a 9lb plate and an 11 lb v-weight... you made the tanks THE SAME WEIGHT. You are just as screwed with the aluminum tanks as the steel tanks.

Anyone that condones aluminum tanks in a wetsuit, blasts steel tanks in a wetsuit, and doesn't dive with ditchable weight is completely FOS... I don't care who they are. They are missing a crucial concept.... the reason one can swim aluminum tanks up and can't swim steel tanks up is either 1) you have too much gas in your steel tanks [easily solved], or 2) you failed step #1 with those steel tanks, or 3) The light nature of the aluminum tanks allowed you to carry enough ditchable weight to offset the compression of the wetsuit.

BUT. Your wetsuit will expand on your way up. So the amount of weight to ditch needs to be less than or equal to the amount of gas you used out of the tanks. If you are 12 lbs negative on the surface at the start of a dive, it's because you have 12 lbs of gas that you are prepared to not have when you return. Then while you're sitting at 130 feet watching your pressure guage while panting profusely and finally realizing my point, you know you have the weight of the gas, plus the weight that you used to offset the buoyancy of your wetsuit.

Lets say you used 1/3 of your gas. You now have 8 lbs of gas. You are 4 lbs lighter than before. If you ditch much more than that, you aren't going to be able to control your ascent when you become to light near the surface [otherwise you wouldn't have survived Step #1].

But is 4 lbs going to be enough weight to make a difference? What about you freeflow it down to 1/3 of your gas remaining. That lets you ditch around 8 lbs. Now is that enough to get you up?

Dunno. Depends how compressed your wetsuit is!

I once had a situation where I dumped a little too much gas out of my BC, and needed to add more. But my deflate button was stuck and the gas coming from the tanks just went right out the oral inflation mouthpiece. Looking back there were a dozen different solutions, but at the time I didn't have many good ideas. I treaded water at 15 ft during the safety stop. It sucked. That was only with a single aluminum.

NOW to take this one step farther, just to make sure I've pissed off -everyone-.

If you are diving a cold water wetsuit, and you know how much gas you need to bleed off in order to ditch enough weight to swim to the surface. Then by all means. Good job. I apologize for calling you a 16 year old floridian debating snow.

BUT if you do believe that you can swim your full doubles rig [aluminum -or- steel], in cold water, while being warm enough [no cheating with dead or thin wetsuits], without ditching anything, from the bottom to the surface.... you are just trying to make up crap to justify the nickel rocketry of not buying a drysuit.

-I- Believe that there is just as much chance of someone being able to do that, as someone being able to swim against a 4 knot current."

 

[Soggy]

To give credit where credit is due, that was written by Spectre (who also happens to be one of the guys I dive with up here in this frozen wasteland).

 

[Dryglove]

To give credit where credit is due, that was written by Spectre (who also happens to be one of the guys I dive with up here in this frozen wasteland).

Read the first line of post. Credit was given

Read this excellent post by spectre in another thread a while back on the same subject http://www.scubaboard.com/showthrea...highlight=steel

 

[Soggy]

Read the first line of post. Credit was given

Yeah, I'm just blind.

 

[mindGrabber]

To give credit where credit is due, that was written by Spectre (who also happens to be one of the guys I dive with up here in this frozen wasteland).

It’s really nice and detailed post.

Concerning the topic (steel or AL) maybe my logic in the thread is unripe and highly black-and-white. In my last posting I was trying to be precise in my words without any additional thoughts and cases:

…basing on idea that AL tanks buoyancy easer to manage. So I’m gonna use AL tanks with both wet and dry suit in sea environment always when it’s possible.

Key words are *AL tanks buoyancy easer to manage*.

If I’ll be unable to rent AL tanks – I’ll dive steel one but if I’ll have a choice – I’ll chose AL tanks.