Diving Dry? Balance your Rig!

[Dive Right In Scuba]

Argon is definitely warmer...depending on your dive. If you're recreational diving, not a huge difference. Go deeper and longer, and you will see the benefits

 

[tracydr]

I'm assuming, because I have not read the book yet, that the method is to put all your gear in the water and then use the scale to measure how much it pulls in either direction? So, a positively buoyant article will be measured with the scale up-side-down as the object pulls towards the surface? I was thinking about trying something like this while we're at the pool this weekend. Measuring each piece of gear separately while at the bottom of the pool to determine net buoyancy and weighting.

unless I'm way off base...

You take all your negative gear ( tanks,backplate,lights,bits and pieces) and attach it to the fish scale with a d-ring. And weigh it in the water. Then, you take yourself, dressed in your drysuit and undergarments, and do your weight check in the pool, in a fetal position, to see how much weight it will take to sink. There are some more details but I'll encourage you to buy Steve's book to read the rest. It's a great read with lots of good stuff on buoyancy,trim,breathing and other great skills.

---------- Post added October 16th, 2013 at 10:11 AM ----------

Yes - don't do it. Your suit flooded will be neutral - have the same impact on your overall boyancy as a bathing suit. So wearing a bathing suit with the rest of your rig will be the same as a flooded dry suit. As Diver0001 says different story getting out of the water - 20 litres of water weighs nothing in the water and about 44 lb out of the water.

So true. I did a pretty good job of flooding my drysuit once and really didn't notice much,until I got out. It was pretty tough climbing the stairs at Catalina Dive Park. And boy did I get cold!

 

[dive_turkey]

You take all your negative gear ( tanks,backplate,lights,bits and pieces) and attach it to the fish scale with a d-ring. And weigh it in the water. Then, you take yourself, dressed in your drysuit and undergarments, and do your weight check in the pool, in a fetal position, to see how much weight it will take to sink. There are some more details but I'll encourage you to buy Steve's book to read the rest. It's a great read with lots of good stuff on buoyancy,trim,breathing and other great skills.

It's already on my reading list. Unfortunately, I'm mid-semester right now, so I'm not permitting myself to purchase recreational books. I find that I'll read an entire 450 page book on diving in about three weeks all the while not reading a single page of a reference needed for a paper due in two days...

We're headed to the pool on sunday, which is locked in due to time available and the drive it takes to get there. I'm bringing the scale and had intended to derive my own method for establishing the negatives vs. the positives. Sounds like I'm already on the right track. If anything, I'll get myself close and take careful notes. Then when I have the opportunity to read Steve's book I'll either make the mathematical adjustments necessary or take another trip to the pool if I'm that far off.

Thanks!

(as a matter of fact, I'm supposed to be writing a three page paper on Conflict Management right now, but my stupid ScubaBoard notifications keep going off, and I welcome the distraction all too much)

 

[Agility]

my stupid ScubaBoard notifications keep going off,

[OT]select "weekly" then the notifications will arrive after your paper is due [/OT]
Don't start reading The Six Skills if you do not have the time to finish it, though if you are very disciplined you might save one or two chapters for later

 

[dumpsterDiver]

So what you are saying is the concept of a balanced rig does not include anything removable. Sorry it does not make sense to me, heck its all removable if you think about it. Here are your words...my underline.

"Not the fill rig, only the non. ditchable part. Those parts that can be ditched (stage bottles, lights, ditchable weight) are not taken into account"

I assumed we just miss communicated. I would contend anything attached to you or your rig will affect if it is/is not balanced. The fact that you can ditch it may help you make an emergency ascent for sure, but as a plan I think it is rather poor, my words were a plan of last resort. There are much better methods that allow more control.

I agree. We should all dive a "balanced" rig.

I think this is a critical issue and it doesn't sound like people are in agreement. MY understanding of that is simple: A rig you can swim up after a complete loss of a BC AND after ditching some ballast (which would be lead, but might also include a big light etc.). Once you reach the surface, expansion of the wetsuit or air in the dry suit, SHOULD allow a diver wearing a "balanced rig" to stay on the surface.

Seems like a simple definition. If we try to modify this definition of (a balanced rig) to stipulate that no lead can be dropped, then it becomes unworkable in cold water with a thick wetsuit, regardless of the tanks..

A wetsuit can compress 20 lbs worth of buoyancy and the weight fluctuation associated with air consumption is 5 or more lbs, so a diver can EASILY be 25 lbs negative on the bottom (with no air in their BC ) and if they have sufficient ditchable lead- they are diving a balanced rig..

Once again the assumptions inherent to the term must be precisely defined before any meaningful discussion can be had about application of the priniciple.

 

[rhwestfall]

Is that because the risks involved in not doing it aren't stressed enough (too much emphasis on "diving is fun") or is there some other reason like divers not taking it seriously?

Robert, I strongly feel that the current time involved in the training of (most) divers in O/W & AOW does not provide the repetition to make it stick or sink in....

add to that perhaps a less that enthusiastic student (diving to check the activity off the list), the claimed "lost leader" that lessons are said to be at a shop, the mentailty of "everyone gets a trophy", etc., etc., etc.,and you have the buildings of a "perfect storm".

IIRC, OW texts covered this (weight check/balanced rig), then and now... its perplexing that it isn't being applied (overweighting students) or utilized (students adhering to the skills).

Yes, the masses here will say they do, yet we still see it happening....

 

[PfcAJ]

i think you have to flush 6 times to be able to see any difference at all. Seems like a lot of argon. That's just from the DAN presentation I watched on exposure protection. I really have no argon experience,whatsoever,

I believe you're referencing a somewhat recent study that compared argon to air as an insulator. For that study, they did flush 6x, and iirc there was a 20% improvement over air. This was all at 1 ATA.

If you dive deep enough, a rather large % of the gas in your drysuit becomes argon without any flushes at the surface. For a shallow dive, you kind of need the flushes to see a marked advantage. For a deep one, maybe not.

 

[rhwestfall]

never mind......

 

[RJP]

??????????

As you go deeper, and deeper you add more and more gas to the suit. Since you're putting more argon in the suit (added to the original air) on a deeper dive vs shallow, the percentage of total gas in the suit that is argon is therefore higher.

For instance, if I start with a liter of air in my suit and add a liter of argon at 30ft to offset squeeze, the gas in the suit is now 50% argon. If I add another liter of argon at 60ft, the gas in the suit is now 66% argon. At 90ft, the suit is now 75% argon. Etc, etc...

(This is just conceptual illustration of the math; not claiming to calculate actual volumes at various depths.)

 

[rhwestfall]

I know. The brain was heading somewhere else on a holiday, and I redacted as you answered. Need some 4 hour Energy, and fast....