A "balanced rig" and how do you achieve it?

[Okiecaver]

I made the regrettable mistake of tackling this subject on another board without really knowing what I was commenting about. I have heard the buzzwords and been taught to regurgitate them but I kneed to know others opinions as to what it is and how it is achieved.

Here to learn

Dive safe
Brock

[MikeS]

Brock,

What do you mean by a "balanced rig"?

Mike

[Okiecaver]

that a balanced rig was one that enabled you to be neutral , to "float", at a depth of 10 feet with 500 psi in your back tank(s) and no gas in your bc.

So what would be the procedure for determining/achieving this?

In my case, I dive steel doubles, Faber or PST 95s, ss back plate, argon bottle, etc.

So what do I do to achieve this?

I made a snide comment on another board, thinking I was clever. Instead it descended into name calling and probably ended a couple of friendships;-0

Thanks in advance
Brock

[detroit diver]

I would get into a pool with all of the gear you always use, including exposure protection, and dump all your air down to 500 psi. On the surface, add or subtract weight until you sink upon exhale, and rise upon inhale from your reg. This might mean that you need to change BP's. My LP104's are too heavy for a SS BP-I had to change to AL.

[ericfine50]

Brock,

I think the AL bp will help. DD is correct, dump to 500 and start taking off weight until you are neutral. Remember the canister light - if you are going from a pro-14 to say a helios, that can affect it as well.

Have a blast. It is fun.

Eric

[MikeS]

Okiecaver once bubbled...
that a balanced rig was one that enabled you to be neutral , to "float", at a depth of 10 feet with 500 psi in your back tank(s) and no gas in your bc.

Brock,

What you have described I know as “proper weighting.” You say tomato …

However, I would modify it to being neutral just below the surface (rather than at 10 feet) with a near empty tank (rather than 500 psi). The point is to be able to achieve neutral buoyancy not only on the safety stop but also as you slowly ascend to the surface after the safety stop.

I like to check it in the pool as Detroit Diver described any time I make a major configuration change, and have it worked out for verious configurations of BC and exposure protection. The shallow end of the pool is the best place; if you have any problems, just stand up. And it's convenient to add or take off weights without loosing them.

I also remove any items that I may detach during the dive, i.e. bailout bottle and reel, before the exercise because I may be making a safety stop without them.

Mike

[WYDT]

detroit diver once bubbled...
I would get into a pool with all of the gear you always use, including exposure protection, and dump all your air down to 500 psi. On the surface, add or subtract weight until you sink upon exhale, and rise upon inhale from your reg. This might mean that you need to change BP's. My LP104's are too heavy for a SS BP-I had to change to AL.

Ditto! I also have an AL plate for Freshwater with my 104's. I use a steel for salt water and it works out very well.

I would say if you're in the pool to dump the gas to 100psi though... and have a buddy in the water with you! You don't want to be buoyant with empty tanks. That could be ugly if there was a bad problem and you still had deco...

Chances are this will be a mute point as I'm still trying to figure out how to get some more weight off me. Nothing else I can get rid of... may be a good excuse to get that 18W Helios! ;)

[Dan Gibson]

Mike,

Try it this way. Put all your exposure protection, fins and mask on and hop in the water. Do not put the rig on. Find out what it takes to just sink you when you exhale. That is how positive your exposure suit, mask and fins are. Repeat this for any combo of exposure protection and write it down.

Now weigh your rig with tanks and full of gas. Use a fish scale. You may have to add weight to get it to sink. Just subtract that off afterwards.

Know what the gas in your tanks weigh. This gives you the positive swing and also tells you what you should theoretically have as ditachable weight.


Now do the math and see what you need to add to you rig to be neutral at your last stop (or surface if you prefer) with no gas left. You will be sharing air in an emergency. This additional weight can be part of the ditchable. You may even find that you can't quite be balanced. A small amount of weight to swim up is acceptable. Many put this at around 10 lbs max. My doubles will put me at 8 lbs negative at the beginning of the dive with air or nirox. Helium improves this slightly. Thats the price for using PST 104s in fresh water. I even use an aluminum backplate.

The above example will get you very close. You may need to add one ot two pounds at best. I mentioned it to a bunch of GUE instructors and instructor candidates in January. Actually, I have to give credit to RJ Myers for showing this to me. We were in a hurry during the March 2002 Fundamentals class at Gilboa. It was a very cold day. This was the quickest way to do it since he already had an idea of what my rig weighed, but not what my exposure protection did for me. I dropped 6 pounds doing this between dives.

[Okiecaver]

I have PST 95s and Fabers. The fabers are a bit more bouyant than the Pressed Steels.

Do I do this twice with each set, subtracting the difference, and adding that to the fabers?
or do what I'd really like to do, sell the fabers on Ebay and buy Nanci LaVakes Pressed Steel 95s? ;)

Aside from my cannister, what else comprises ditchable weight?

Dive safe
Brock

[ericfine50]

Stages, canister light, video camera - Anything that you could ditch that would allow you to move up in the water if you have a massive wing failure.

Eric

[MikeS]

Dan Gibson once bubbled...
Mike,

Now weigh your rig with tanks and full of gas. Use a fish scale. You may have to add weight to get it to sink.

Dan,

This threw me for a loop. I want to know the negative buoyancy not the actual weight. So I’m guessing that you weight the rig while it's in the water?

Mike

[padiscubapro]

Anotherpoint that no one else mentioned.. If you are going to dive with sling bottles you must account for them.. they will add negative buoyancy at the start but slings are usually alumini`um and get positive at the end of a dive.. most people dive with the smallest slings they need so they are very likely to go positive..

al 80s as slings could be over 3lbs positive each.
some oof the smaller tanks are just as bad..

[Dan Gibson]

Yes,

Weigh it in the water when the tanks are full. Subtract the gas weight and you know the buoyancy when empty. Use a fish scale.


MikeS once bubbled...


Dan,

This threw me for a loop. I want to know the negative buoyancy not the actual weight. So I’m guessing that you weight the rig while it's in the water?

Mike

[MikeFerrara]

I was under the impression that the term "balanced" refered more to where the weight was than how much! It goe without saying that you should be properly weighted.

I thought it meant that you had just enough ditchable weight or that you didn't need any to get to or stay at the surface. At least that's what they lead you to believe in the GUE book.

BTW if your neutral at 10 feet with a near empty tank is the plan to do an uncontrolled ascent from there to the surface if your low on gas. that would be mean that in a cave you would be plastered to the surface. I think you need to neutral at the surface with near empty tanks.

[Dan Gibson]

I thought balanced rig was one of the GI coined terms. It seems to have made its way into the GUE courses, although that isn't important. Trim refers to you attitude in the water. Placement of the weights affects trim. Some of the terms may mean one thing to one person and another to someone else. The important thing is to get it right. It makes diving much more enjoyable and safer.

I would also agree that you should really be neutral at the surface and not at 10 feet.



MikeFerrara once bubbled...
I was under the impression that the term "balanced" refered more to where the weight was than how much! It goe without saying that you should be properly weighted.

I thought it meant that you had just enough ditchable weight or that you didn't need any to get to or stay at the surface. At least that's what they lead you to believe in the GUE book.

BTW if your neutral at 10 feet with a near empty tank is the plan to do an uncontrolled ascent from there to the surface if your low on gas. that would be mean that in a cave you would be plastered to the surface. I think you need to neutral at the surface with near empty tanks.

[MikeFerrara]

Dan Gibson once bubbled...
I thought balanced rig was one of the GI coined terms. It seems to have made its way into the GUE courses, although that isn't important. Trim refers to you attitude in the water. Placement of the weights affects trim. Some of the terms may mean one thing to one person and another to someone else. The important thing is to get it right. It makes diving much more enjoyable and safer.

I would also agree that you should really be neutral at the surface and not at 10 feet.




Dan,

You misunderstood me I think. I know what trim is thanks anyway. LOL

When I refered to weight placement I meant ditchable vs. not-ditchable. sorry

In otherwords balanced rig = ...
Not over weighted
just enough ditchable weight to enable you to surface or stay at the surface without having so much ditchable as to turn you into a racket.

[Dan Gibson]

I guess I did misunderstand you. I thought you meant balanced as in the location of weights on the body relative to the cg. Yes, the GI explanation is exactly about ditchable weight and the ability to swim up the rig. Funny thing is balancing your weight forward and aft (i.e. trim) is part of the Fundamentals class.

It's amazing how this medium does not lend itself to an easily understandable explanation. That is what is nice about getting info from knowledgable instuctors in person.





MikeFerrara once bubbled...


Dan,

You misunderstood me I think. I know what trim is thanks anyway. LOL

When I refered to weight placement I meant ditchable vs. not-ditchable. sorry

In otherwords balanced rig = ...
Not over weighted
just enough ditchable weight to enable you to surface or stay at the surface without having so much ditchable as to turn you into a racket.

[MikeFerrara]

Dan Gibson once bubbled...


It's amazing how this medium does not lend itself to an easily understandable explanation.





Especially for someone like me who needs his hands to talk. LOL

[DIR Tec Diver]

Properly weighted = neutral buoyancy at safety stop or last deco stop depth (6 meters)

Properly trimmed = you hold perfect horizontal position in the water being pulled from neither side nor front/back

Everyone is different. You need to try what works best for you and how you feel most comfortable. We can talk all day about "what I do", but you definitely need to do it in the types of water you will dive in. If it is fresh water, go to a pool, in salt water, guess what??

It is fun, and you should not be bashed for asking like at the previous board. At least you are thinking. Only stupid people who suggest stupid things need to be prepared for a pounding.

have fun.

[MikeFerrara]

DIR Tec Diver once bubbled...
Properly weighted = neutral buoyancy at safety stop or last deco stop depth (6 meters)



Followed by an uncontrolled ascent from 6 meters to the surface ? Good plan!

You need to be able to achieve neutral buoyancy at any depth with a near empty tank in order to be able to control the ascent all the way to the surface.