Let's talk about balanced rigs

[Doc Intrepid]

"...However the heavy exertion required to do so is not recommended for a variety of reasons. Contingency planning and practice is the best option."

+1

"Balanced Rig" is the tooth fairy of technical diving. You can talk about it all you want, but its still a myth.

With a set of steel 130s, an 80 and 40 of 50 and 100%, and a Luxfer 14 argon bottle, I'm coming close to 30 lbs of gas and ancillary weight at the front end of the dive. Adding a third sling tank, or 2 Luxfer 80 stages instead of 40s, and the difficulties are compounded. And I don't even start to factor in the weight of some of the cameras some of these guys are using. (Scooters don't weight much, but I don't think I'd jettison mine - probably use it to drag my butt back up!)

If I tried to swim that much weight up up from 150 fsw or so I'd vapor lock from CO2 saturation. (So would some guys half my age. That's a lot of heavy exertion under undesirable circumstances.)

The point is that with a team you shouldn't need to exert yourself like that. There are other, safer, more professional response alternatives than "swimming your rig up yourself" from however deep you find yourself (especially in situations where there is no hard bottom!).

So while its okay to debate how many angels can dance on the head of a pin, recognize that at the end of the day people are talking smack. The safer alternative, as CD already noted, is to plan for such a contingency as a team, and then practice your planning.

Just MHO.

YMMV.

Doc

 

[Slonda828]

I'm I can dive with no weights wearing a 3 mil shorty BPW and an AL80 in warm caribbean waters.

Using the same exposure suit and BP with double LP 108's I've done a simultated wing failure by dumping all the air from my wing and swimming the full tanks to the surface from a training platorm at 20' in a local lake, then orally inflating the wing while I continued to tread water on the surface.

In this configuration, I'm extremely negative which is why I either dive it dry, or carry liftbags, but it is possible for me to swim it up.

However the heavy exertion required to do so is not recommended for a variety of reasons. Contingency planning and practice is the best option.

I have to agree with you here. I can dive a 3mm with no weight at all in warm water. When I wear my Bare XCD2 tech drysuit, DUI polartech powerstretch undergarment, and use my HP120 I am easily 7-8 pounds negative at the start of the dive. That's why I have a BC, a drysuit, and a lift bag. Can I swim my rig up? Yes, I've tried it. It's not very pleasant though, and I am a darn good swimmer. It reminds me of treading water with my rifle over my head. I think this is simply a case of "Yeah, I can swim it up, but I really do not want to ever actually have to do so."

I am also a big fan of using releasable weight on my NTEC rig that is equal to the total amount of gas in my tank. With a HP120 that is about 8 lbs (ballpark). So I put 4lbs in each weight pouch on my rig so that if all hell breaks loose at depth (with a full tank) I can ditch one or both pouches to be neutral with a full tank. That way I have my BC, my drysuit, my lift bag, and ditchable weight. I like options. I am not sure if GUE encourages or precludes releaseable weight, so I am not an expert in that matter.

 

[H2Andy]

plan for such a contingency as a team, and then practice your planning.

of course

but what if you get separated from your buddy?

are you fully consciously aware that you are diving a rig you can't swim up on your own or are you just ignoring that fact?

shouldn't you at least be carrying additional bouyancy in case both your wing and suit fail?

 

[Cave Diver]

but what if you get separated from your buddy?

:shocked2: Then you're gonna die!

Seriously tho, a buddy is there to lend support to the team, not to be a crutch to someone incapable of doing the dive. If you're not self sufficient enough to do the dive on your own, you probably shouldnt be doing it with a buddy either.

I have one main buddy that I dive with and I'll do almost any dive with him. It's not that I rely on him to keep ME out of trouble, but that I can count on him not to get into any trouble that I'll have to get HIM out of and he expects the same of me.

are you fully consciously aware that you are diving a rig you can't swim up on your own or are you just ignoring that fact?

shouldn't you at least be carrying additional bouyancy in case both your wing and suit fail?

Yes, I'm aware that the weight of the rig may be more than I can swim up from the bottom on a deep dive.

The odds of a complete loss of bouyancy from wing AND drysuit during the same dive is so small as to not even be a consideration as far as I'm concerned. A drysuit would have to be ripped or shredded in multiple spots to not be able to trap air somewhere and provide bouyancy.

It may not be optimal but it would be workable.

As I previously stated, lift bags/smb are part of my kit on any open ocean dives, whether using a drysuit or not. In addition to providing a method for surface signalling, they can be used to recover something from the bottom or as an alternate method for providing bouyancy.

 

[Doc Intrepid]

of course

but what if you get separated from your buddy?

are you fully consciously aware that you are diving a rig you can't swim up on your own or are you just ignoring that fact?

shouldn't you at least be carrying additional bouyancy in case both your wing and suit fail?

You're right, occasionally despite all your planning the situation can simply go to hell. In my case, in addition to my wing and drysuit, I carry two closed circuit devices - a 6' H SMB, and a H 300 lb lift bag. Additionally, I do have a Gavin, and while I was joking earlier, scooters change the equation in a number of different ways. If separated from the team by some catastrophic event, I can ascend independently. As CD says, it may not be optimal, but its functional. But I carry those items as not just 'my' gear, but as team options - available to whomever may have issues. My plan is to dive as a team.

I would like to think that despite my inadequacies I make the team stronger by being an autonomously-capable member of it.

There are no foreseeable events (that I'm aware of) where I've said in effect: "well, if X happens, then I just die". I'm aware that there is a school of thought in diving that is comfortable with accepting greater risks based on a logical deduction that the precipitating event is unlikely to occur ("Alpinist", from mountaineering), but it isn't a school of thought I'm comfortable with.

FWIW...

Doc

 

[JeffG]

+1

"Balanced Rig" is the tooth fairy of technical diving. You can talk about it all you want, but its still a myth.

With a set of steel 130s, an 80 and 40 of 50 and 100%, and a Luxfer 14 argon bottle, I'm coming close to 30 lbs of gas and ancillary weight at the front end of the dive. Adding a third sling tank, or 2 Luxfer 80 stages instead of 40s, and the difficulties are compounded. And I don't even start to factor in the weight of some of the cameras some of these guys are using. (Scooters don't weight much, but I don't think I'd jettison mine - probably use it to drag my butt back up!)

If I tried to swim that much weight up up from 150 fsw or so I'd vapor lock from CO2 saturation. (So would some guys half my age. That's a lot of heavy exertion under undesirable circumstances.)

The point is that with a team you shouldn't need to exert yourself like that. There are other, safer, more professional response alternatives than "swimming your rig up yourself" from however deep you find yourself (especially in situations where there is no hard bottom!).

So while its okay to debate how many angels can dance on the head of a pin, recognize that at the end of the day people are talking smack. The safer alternative, as CD already noted, is to plan for such a contingency as a team, and then practice your planning.

Just MHO.

YMMV.

Doc

I had a big long post about why this is a load of BS...but then I lost the post.

So here I go again. (short version)

Camera's, scooters, 40's, 14 are close to neutral and can also be jettisioned. So they are not part of the equation.

It is not a "myth". Some rig's lend themselves to be balanced...others not so much, but hardly a myth. Backgas with nitrox in big doubles are always hard to balance.

The first thing is you need to do is to actually understand what a balanced rig is.

But you made enough mistakes in your post...that it is you talking "smack".

 

[Bismark]

of course

but what if you get separated from your buddy?

are you fully consciously aware that you are diving a rig you can't swim up on your own or are you just ignoring that fact?

shouldn't you at least be carrying additional bouyancy in case both your wing and suit fail?

I think it is also important to note that Doc's max weight is at the beginning of the dive. At that point, all those stages, deco bottles, can light, etc., are expensive ditchable weight. But I would sure as hell jettison them with extreme prejudice if I had to. At the end of the dive, those 80's and maybe 40's are empty (or you have some deco gas but you have consumed some of your backgas and the weight of the gas is reduced.) and positively buoyant. The can light is about 2lbs but could still go. At that point, if you did your math right, even a 6lb lift SMB (3ft H closed circuit variety) could make a lot of difference. Moreover, how many failures are you planning for here? Generally, we plan for one major failure and then get the hell out of dodge. Wing failure and drysuit failure? At the same time? I would have been heading home with the first failure. I would also classify buddy seperation as a major failure and abort the dive.

 

[Slonda828]

The first thing is you need to do is to actually understand what a balanced rig is.

I'm genuinely curious...what is your definition of a balanced rig?

 

[JeffG]

I'm genuinely curious...what is your definition of a balanced rig?

Here are a couple of some fun threads for you.

http://www.scubaboard.com/forums/dir/208063-balanced-rig.html


http://www.scubaboard.com/forums/dir/77558-aluminum-vs-steel-tanks.html

 

[Slonda828]

Here are a couple of some fun threads for you.

http://www.scubaboard.com/forums/dir/208063-balanced-rig.html


http://www.scubaboard.com/forums/dir/77558-aluminum-vs-steel-tanks.html

Dude that thread is hilarious. Thanks man.

So my hp120 singles rig is balanced because I have ditchable weight that is equal to the weight of the gas when my tank is full. This means that if I cannot swim my rig up when it is full (which I can), then I have my drysuit or SMB in case of primary wing failure. This also means if I get smoked or cannot manage my drysuit (or lose my lift bag) that I can cut 4-8 pounds of weight and (depending on the amount of gas that I have consumed) be neutral. This generally fits in with the concept of balancing your rig, right?