Question about “balanced rigs” and having all ballast unditchable

[johndiver999]

I too am a solo diver who places great faith in things like physics and accident reports.

It is my perception that few (if any) fatalities are averted by ditching weight. In fact, it is my perception that it is rare that any diver ditches weight intentionally in an actual emergency.

Here's why. The only circumstances where ditching weight is a wise choice is when a diver is at the surface and is having trouble staying there. Usually that happens with newly minted divers who are panicking, and they can't ditch weight any more effectively than they can inflate their BC. An experienced diver unable to stay at the surface has other things to try, and usually won't ditch because it's expensive and a hassle to replace integrated weight pouches.

I use a weight belt and typically carry some ditchable weight however it is under my crotch strap and won't come off in one motion the way I was taught. There are some dives where I am properly weighted without adding lead. I avoid configurations where I am overweighted without adding lead but if it is just by a pound or two I'll do it.

I don't believe that, in my particular situation, having ditchable weight contributes to safety.

What if someone has a tank failure and starts sharing air with you and you have too small of a reserve. Might it be nice to drop the victims 6 or 8 lb weight belt to ensure you both get to the surface?

What if you have a scuba failure and are trying to kick up initially and you run out of air and get a bad leg cramp? Might it be nice to drop the belt or lead and ensure an ascent?

People that are underwater with unditchable ballast are putting themselves in a precarious position. If you are hundreds of feet in a cave or have an hour of deco, an immediate exit to the surface is not an option, but for recreational no deco divers, dropping some ballast is an important option.

Even in an emergency situation that is using all the divers resources to manage and remain calm and avoid panic, is there not some value in knowing inthe back of your mind, I can still drop my belt - as a last resort.

I think there are lots of scenarios where having the option to ditch ballast at depth is beneficial. What if you are bringing a buddy up who is out of air, he fails to vent bc, starts shooting up, then becomes separated, screws up and completely dumps bc and then plummets, alone to the bottom with no air to breath or to inflate bc. A yo yo screwed up ascent with recreational divers in a true emergency is Not unheard of.

Divers make it to the surface often and then sink and die. Maybe they forget to ditch lead, but I would rather be vulnerability to forgetting, then to have no option.

I don’t agree with the idea that the only time ditching lead is beneficial is on the surface and in some regard, it is irrelevant because if you have the ability to ditch on the surface (which many people think is beneficial) then you also have the OPTION of dropping at depth.

 

[Colliam7]

A worthwhile discussion, here. While at least one SB member has suggested we move this out of Basic, we are leaving it here because the issue Eric raises is really 'basic' to safe diving practice.

1. I agree with lowviz and others - I have never considered ' balanced rig' and 'no ditchable weight' to be the same thing. Furthermore, I don't have a particular sense that such a view has become a standard of practice.

2. For me, I believe (and tell recreational students and divers) that you need a) sufficient weight to initiate a descent (and that doesn't mean rocket ride to depth, just enough to get you strated), and to hold a safety stop at 15 ft with a cylinder with minimal remaining gas (e.g. 300-500 in an AL80) and b) no more weight than you can swim to the surface in the event of a BCD failure. That is the 'window' of weighting for me.

3. I am not aware that a practice / goal of no ditchable weight has become commonplace, so I cannot answer Eric's question, but welcome all insights, such as those already shared.

4. Perhaps I am fortunate, that I need some weight (2lbs) even with my weightiest single cylinder rig (SS BP and HP120).

5. It is important not to underestimate the effects of ditching even a minimal amount of weight (2-4 lbs).

I do wear a weight belt (Mako rubber freediving belt) with my BP.

From my perspective, I think that Eric's raising of the issue is beneficial, for those of us who advocate a 'balanced rig' - to be sure that we are clear on what that terminology means - and for other divers who may be hearing 'no ditchable weight' being bandied about as a goal, not simply an occasional situation.

 

[johndiver999]

Okay, it's a misnomer. I agreed in post #4 above, and I suspect most others might agree. Someone posted the link to the GUE gear configuration, where it says:

The diver should be able to drop unnecessary weight and swim up without a functioning BC. As with all diving, the key component to proper buoyancy is diving with a properly balanced rig.

The definition of balanced seems to be very unclear.
You seem to be defining it as balanced AFTER the ditching of ballast in an emergency.

Some other people define balanced as being able to swim the rig up with no bc use and no dropping of ballast.

The difference in definition is HUGE, particularly when you are talking cold water and thick suits. The divergence in the definition of the term makes discussions very confusing.

The older d-I-r definition included the ditching of ballast as inherent in the definition.
This is an integral part of their advice to avoid double heavy steels in the ocean and instead use over filled
Aluminum 80,s and a weight belt. These are not trivial distinctions.

 

[Bob DBF]

Your reg will most likely allow for backflow. Do the math, how much more do you 'weigh' if your tank becomes full of water. Or is that an impossible scenario that you don't need to consider?

It's not weight you need to worry about, unless you are carrying it out of the water, but the loss of buoyancy. So say an Al 80 with 4.4# of buoyancy empty will loose that when full of water. If I was worrying, it would be about where my next breath was coming from.


Bob

 

[lowviz]

My weighting goal speaks to @Colliam7's point #4. I'll bolt whatever weight on me that I need to be neutral with no air in my suit, BC, or wing MINUS the weight of gas in whatever I'm diving.

Then I add the weight of gas (OK, plus whatever comfort factor is desirable) as lead on my W/B. Realize that lead on your belt could be gas in your tank. But sometimes lead translates to suit inflation and warmth or really rockin' buoyancy on the surface in rough seas. It is a choice...

So I go in negative, but could quickly establish neutrality by dropping my W/B. As I use the gas, dropping the W/B becomes unnecessary.

#1 Rule in scuba diving: Always have something to breathe.

 

[lowviz]

It's not weight you need to worry about, unless you are carrying it out of the water, but the loss of buoyancy. ...//...

We are coming at this same thing from opposite directions.

Weight/loss of buoyancy, take your pick. A pint of water is a pound negative and a pint of air is a pound positive...

EDIT:
Ah! I think I get your drift. A pint of water (underwater) doesn't weigh anything. My thinking is that it represents a loss of a pint of air in a tank as a tank remains constant in volume no matter what is in it.

 

[2airishuman]

What if someone has a tank failure and starts sharing air with you and you have too small of a reserve. Might it be nice to drop the victims 6 or 8 lb weight belt to ensure you both get to the surface?

I would like to start out by observing that all the scenarios you paint involve multiple failures.

I will not be found in a situation where I am helping someone else and have such a small reserve left that inflating my BC or (orally) inflating someone else's BC is not feasible.

What if you have a scuba failure and are trying to kick up initially and you run out of air and get a bad leg cramp? Might it be nice to drop the belt or lead and ensure an ascent?

If that happens, I'll ditch my kit.

People that are underwater with unditchable ballast are putting themselves in a precarious position. If you are hundreds of feet in a cave or have an hour of deco, an immediate exit to the surface is not an option, but for recreational no deco divers, dropping some ballast is an important option.

Even in an emergency situation that is using all the divers resources to manage and remain calm and avoid panic, is there not some value in knowing inthe back of your mind, I can still drop my belt - as a last resort.

There are pros and cons. I take a holistic approach to buoyancy management. Unintended loss of ballast poses its own risks. I will not lose my ballast by mistake. I will not have my kit rocket to the surface if I take it off to try to free it from some fishing line or whatever. To gain these benefits, there are some situations where I am using no wetsuit or a very thin wetsuit, and end up diving without ditchable ballast or with very little ditchable ballast.

I think there are lots of scenarios where having the option to ditch ballast at depth is beneficial. What if you are bringing a buddy up who is out of air, he fails to vent bc, starts shooting up, then becomes separated, screws up and completely dumps bc and then plummets, alone to the bottom with no air to breath or to inflate bc. A yo yo screwed up ascent with recreational divers in a true emergency is Not unheard of.

Well, anyone whose dive skills are such that a situation like that is likely, probably should dive with ditchable weight. And an instructor.

Trying to ditch someone else's weights at depth would be a last resort for me. Donate air, yes. Inflate their BC for them, yes. Swim them up, yes. Pull them up by inflating my BC, maybe as a last resort.

Divers make it to the surface often and then sink and die. Maybe they forget to ditch lead, but I would rather have the vulnerability to forgetting, then to have no option.

I always have the option to ditch my weight at the surface, because I can ditch my kit. It's an emergency, right? If my kit can't provide me air to breathe and cannot be made positive, it's of no use to me, so I'll ditch it and come back for it another day.

I've seen the eyes-glazed-over-can't-make-a-decision behavior. More than once. People in that "box" can't ditch their lead any more than they can inflate their BC.

 

[Dave Bevan]

The term “balanced” had a different meaning years ago. It was separate from properly weighted, which everyone should be anyway. What it meant was that you and your rig were weighted equally so that in the event that you removed your rig underwater for whatever reason, you were weighted neutrally and your rig was also weighted neutrally at depth. This was the definition of “balanced”. You could remove your rig and neither you or your rig would go up or down. Lobster divers in Southern California distribute weight this way so they can remove their rigs at the entrance to a cave and go in separate from their S.C.U.B.A. on a 15’ or 25’ hookah line to grab bugs.
And please don’t tell me that nobody ever removes their rig at depth, because they do. If you never need to remove your rig at depth then you’re not diving in a location where it happens. They teach this around here for kelp entanglements.

So now “balanced” means being able to swim your rig to the surface in case of a wing failure and no drysuit, weightbelt or not.
To me that just means “properly weighted” or minimally weighted and not having to drag up a bunch of extra weight that doesn’t need to be there, and also having the common sense not to dive too deep in a thick wetsuit without some sort of redundant lift.

Nobody has answered my question yet, where and why did the practice of no ditchable weight come from?

I'll answer your question. I assume you are talking about the 'Balanced rig' which is from the GUE manual as you are using it in reference with BP/W/DIR.

This is taken directly from 'DIR - The Fundamentals of better Diving' by J Jablonski 2000.

Buoyancy Compensators

"Many divers mistakenly believe that they must have large buoyancy
compensators to support their diving needs. Actually, divers do not need
excessive amounts of lift; large wings, because of the additional material
they require, only serve to increase drag. However, if, in fact, a diver does
need more than 65 pounds of lift for diving doubles, or more than 30
pounds for diving singles, then they do not have a balanced rig and are
an accident waiting to happen. The diver should be able to drop unnecessary
weight and swim up without a functioning BC. Use of large steel
cylinders indicates an aggressive dive, one that should only be done in a
dry suit, which provides not only good insulation but also additional lift.
As with all diving, the key component to proper buoyancy is diving with
a properly balanced rig.

Divers using dual BCs have experienced an array of problems; these
include increased drag, additional task loading and uncontrolled inflation.
There is never a need for “redundant buoyancy” in a properly
balanced rig. A small leak from the inflator can continually add air to an
unaware diver’s BC. As the diver becomes more positive, s/he will usually
try to empty his/her primary BC, all the while remaining unaware
of the secondary inflation. If the diver is unable to correct this problem
quickly enough, s/he may find her/himself at the surface experiencing
any number of problems. The DIR approach avoids the use of dual BCs,
and instead stresses proper balance between BC, cylinders, weighting and
exposure suit."

Many have mistaken this as meaning having no ditchable weight when in fact as the article states its just not true. It is about having the proper balance between all the items. I

 

[lowviz]

@2airishuman, I get (that you get) that one devolves to patterned behavior in times of stress. Thus, I really like instructors who correct students who use a power inflator on the surface.

Nope. Breathe from the big free blue tank in the sky and fill your kit it for free. If you ever end up on top in a crisis, just keep doing what you always have done...

 

[Colliam7]

I'll answer your question.

However, if, in fact, a diver does need more than 65 pounds of lift for diving doubles, or more than 30 pounds for diving singles, then they do not have a balanced rig and are an accident waiting to happen. The diver should be able to drop unnecessary weight and swim up without a functioning BC.

The DIR approach avoids the use of dual BCs, and instead stresses proper balance between BC, cylinders, weighting and exposure suit."

Many have mistaken this as meaning having no ditchable weight when in fact as the article states its just not true. It is about having the proper balance between all the items.

So, the answer is that 'many have mistaken . . '. I agree with your point, Dave, that the DIR wording is crystal clear. So, I do have to wonder, how could such a disconnect arise? At least one post in this thread even alluded to that mistaken impression:

Some other people define balanced as being able to swim the rig up with no bc use and no dropping of ballast.

Maybe, it is a question to which no satisfactory, informed answer is possible. But, hopefully this thread has alerted many divers to the fact that 'balanced rig' is NOT synonymous with 'no ditchable weight'.