Ok, a serious question about balanced rigs

[JeffG]

It set my sarcasm detector off. But I don't know his internet persona very well, I may have mis-calibrated.

It was both at the same time. (sarcastic and real)

Best type of sarcasm...keeps people on their toes.

 

[jeckyll]

....So I think that the best you could do with fixed floatation doo-hickies would be to balance the back gas cylinders. I conjecture, you could arrange things such that the twin 120s are balanced, and if you hover at 10' with empty cylinders the only air needed would be to compensate for the weight of the slung 40s less their buoyancy.

I think you're going about this the wrong way around. Just pick the gear so that your rig is balanced.

Done.

Or you could try to make every rig "balanced" by coming up with more complicated scenarios with weird floating bits to offset your initial, unbalanced, configuration.

To understand it better, IMO, make it about a specific dive that you already know how to do. Then work out what the right gear setup is.

 

[Doc Intrepid]

Some sets of doubles lend themselves to being "balanced" easily. Others not so much.

Double Al 80's balance quite nicely. Double 130's in fresh water (with nitrox) are almost impossible.

Addition equipment will either make the system worse or better.

You only have to answer to yourself, so do whatever floats your boat...everything else just provides amusement on the internet.

Reg,

Jeff's response here is worth your consideration. After you get past a certain point, which different divers will define differently, the concept of 'balanced rig' becomes somewhat utopian. Something to blather about on the internet.

The St. Augustine lies in 250' of cold dark ocean, several hours by charter out of Ocean City, MD. If I dropped on her again, that far offshore in the Atlantic, I'd be using a set of E8-130s with a 6lb SS plate (and no other weight). I'd also have a luxfer 80 with a 120' mix, and 2 Luxfer 40s - 70' and 20', and a Gavin. Just the weight of the compressed gasses alone would be impressively negative. Add the rest, and if I had issues on the front end of my bottom time and tried to swim that much weight up from 250' I'd black out from build-up of CO2 before anything else occurred.

The whole concept of a 'balanced rig', past a certain point, becomes meaningless.

OTOH, I have two buddies and all three of us have scooters. Plus, we have plenty of gas and an anchor line. I'm not going to perform some sort of convoluted CESA from 250', we're calmly going to abort and execute an ascent.

It's more a matter of how you look at things.

By all means continue discussing 'balanced rigs', if that floats your boat. But recognize that dive planning with a team, depending on what sort of diving you're doing, is a more central issue than ensuring you all dive "balanced rigs".

Just MHO. YMMV.

Doc

 

[JeffG]

The St. Augustine lies in 250' of cold dark ocean, several hours by charter out of Ocean City, MD. If I dropped on her again, that far offshore in the Atlantic, I'd be using a set of E8-130s with a 6lb SS plate (and no other weight). I'd also have a luxfer 80 with a 120' mix, and 2 Luxfer 40s - 70' and 20', and a Gavin. Just the weight of the compressed gasses alone would be impressively negative. Add the rest, and if I had issues on the front end of my bottom time and tried to swim that much weight up from 250' I'd black out from build-up of CO2 before anything else occurred.

See..and I would use an Alum plate with a small weight belt. and I wouldn't be using a Gavin...(thats your problem right there ) I'm an X Man LOL


Edit: and a 40 for the 120' bottle as well.

 

[Reg Braithwaite]

keeps people on their toes.

Given your avatar, I have visions of us "dancing" as you machine gun the floor beneath our feet ;-)

 

[TSandM]

I have visions of us "dancing" as you machine gun the floor beneath our feet ;-)

I think Jeff does, too.

I get the weird feeling that "balanced rig" is being used to mean a lot of things here. My understanding is that, if you lose all buoyancy from your wing, you should a) be able to swim the rig with full tanks to the surface, or b) have some weight you can drop to be able to do it, or c) have some redundant buoyancy which will allow you to do it. I think scooters, lift bags, buddies, anchor lines and such come under the category of redundant buoyancy. It's really common sense . . . You don't want to be stuck on the bottom because you can't GET to the surface. Make gear and exposure protection choices to avoid it if you can, and at the point where you can't, make sure you have other ways to return to the surface, as Doc Intrepid describes.