Question about “balanced rigs” and having all ballast unditchable

[CT-Rich]

A lot of new divers are going to buy 7mm suits and not realize that they get paper thin at 100’. That is why we need to be talking old school basics. SB tends to lean heavy on DIR, GUE and tech. My eyes glazed over as you guys started going over places you can hang weights so yo can maintain ninja like trim. Weirdly, I am told I keep pretty good trim and I am not agonizing over where to hang weights. Belt on me with my wetsuit and pouches on my BCD. I have a DUI harness for my drysuit and the same BCD with weights. Part of this whole diving thing is active swimming, the better you are the less it requires. The bubble of air in your BCD can move far more than your weights ever will so how you orient in the Water can be do all sorts of things to your trim as much as anything else...

Almost all of my weights are ditchable. A good belt buckle is an investment, buy steel and avoid nylon buckles, they lose grip with age. Stretchy belts are probably nice, the soft pack belts are pricier.

And to all those who say as a last resort they would ditch $2-5,000 gear, please tell me about all the people that you’ve seen doing it, practicing it or even read about... if it happens at all, they are probably not staying with diving when they realize how much will spend on a new rig.

If you can’t explain how you are going to tell me you are going to fashion water wings from your SMB, make sure you have ditchable weights. If you posted any way to stay buoyant at the surface that was not demonstrated in OW, go buy ditchable weights. If you mentioned a skill that you have never tried, make sure you have ditchable weight.

 

[Jay]

re comments in this thread about the word "ditching" weight(s) and how it could be lost in context / intended meaning / easily mis-read:

Ditching: some weight at depth (perhaps incrementally or in a calculated / guesstimated fashion) vs. some/all weight at the surface vs. ditching all weight at depth (at once) ...

... are obviously all very different (meanings / effects).

And with the latter (ditching all at once at depth) not yet entering a semi-realistic scenario I can think of.

 

[Bob DBF]

...but from my understanding they were expensive (relatively speaking) and people didn't trust them like they do today.

So expensive that I didn't get one. A buddy has a brick, Orca Edge, and you are right, he trusts it more now than when he bought it.


Bob

 

[Bob DBF]

all those who say as a last resort they would ditch $2-5,000 gear, please tell me about all the people that you’ve seen doing it, practicing it or even read about... if it happens at all, they are probably not staying with diving when they realize how much will spend on a new rig.

Well first, I don't dive with $2-5,000 worth of gear to begin with, even if I bring along my camera and a pony I most likely don't break a grand. I learned to ditch gear and swim back before BC's as a last ditch emergency procedure, like dropping weight only more so. I only got close once, but got lucky. As for staying with diving, it wouldn't be the money, it would be the situation that I got into the mess that would make me think twice.

I wouldn't expect anyone to practice or even read about it, but then again OW divers read about dropping their weight belt, but how many practice? Or drop when necessary?

There was a thread in accidents that 5 divers went missing, the current was taking them away from their boat and an island. One diver ditched his rig swam to the island and was the first to alert the authorities. He was one of three that survived.

Bottom line is which is worth more, your gear or your life.



Bob
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I may be old, but I'm not dead yet.

 

[RainPilot]

The bolded statements may work great for warm water diving and little or no wetsuit, but they are not applicable to a two piece 7 mm wetsuit on a deep dive.

Again this is an example of trying to apply general statements, but they don't apply in certain situations. Wetsuit compression effects can easily be 15 or 20 lbs (or more) which is considerably more than the weight of the gas in a "recreational" diver's single tank.

Most people are going to be able to "kick up" the weight differential associated with a single tank, but the wetsuit compression can be 4 or 5 times larger (in certain situations).

I may be missing something. Are assuming the diver is wearing a dry suit or a thin wetsuit? In cold water a diver in a 7 mil wetsuit can need 30 or more lbs of weight. An AL80 holds around 6 lbs of gas. On a dive to 60 feet or so, the suit will lose about 20 lbs of buoyancy If you have a problem, dropping 6 lbs may not be enough to make the rig light enough to kick up, let alone neutral. I know that is why many agencies recommend wearing nothing more than a 5 mil wetsuit and a dry suit for anything colder.

My apologies, all the above is assuming nothing thicker than 5mm when deeper than 100’. If you have a 7mm on then the principle does still apply but the amount you have to swim up increases. At some point it may not be possible to swim it up then you need to accept an uncontrolled ascent at some point in the dive.

If I dived like that I would obviously change the amount of ditchable weight I had. I would also ensure I had redundant buoyancy.

 

[northernone]

I learned to ditch gear and swim back before BC's as a last ditch emergency procedure, like dropping weight only more so. I only got close once, but got lucky. As for staying with diving, it wouldn't be the money, it would be the situation that I got into the mess that would make me think twice.

I wouldn't expect anyone to practice or even read about it, but then again OW divers read about dropping their weight belt, but how many practice? Or drop when necessary?

-snip-

Bob
-----------
I may be old, but I'm not dead yet.

I'll add agreement...

And unfortunately another data point. As a beginner I jammed my tank badly enough in a sunken tree the ability to do a calm "doff and dash" is what I credit for my survival. I am glad I had learned if necessary to leave my primary air source and slowly swim up to my secondary air source (surface). Didn't think much of it at the time, minor annoyance.

... Went back down breath hold diving and wrestled the equipment free. (For those reading, freediving immediately after scuba diving increases DCS risks, don't)

Glad I had my weights separate from my rig, uncontrolled ascent is unnecessarily risky when a partial weight is possible with a little planning.

Cameron

 

[Akimbo]

Glad I had my weights separate from my rig, uncontrolled ascent is unnecessarily risky when a partial weight is possible with a little planning.

I did some experimenting several years after I started diving to figure out how much weight I could drop and reasonably control my ascent rate. Keep in mind that the maximum ascent rate was 60' or 18M per minute then. I tied about 50'/15M of line from my weight belt to a surface float.

I was using a pretty heavy wetsuit with 3 layers that required about 25 Lbs/7.6 Kg to reach neutral at 10'/3M. I transferred about half the weight to a second belt that I didn't drop and started testing. I moved about 2 Lbs/1Kg to the belt I dropped for each test. I found I could drop 22 Lbs/10 Kg before I got uncomfortable controlling the ascent. YMMV.

I used the data from that exercise ever since, but more important is the self-confidence and "feathering" techniques to slow ascent. I have never had to drop lead, but knowing that I can and what it feels like eliminates any apprehension to dump lead. It really doesn't matter that the current ascent rate is half as fast, safety stops are recommended (not required), or you even have a small decompression obligation. The important part is to have a reflexive plan that addresses these priorities, not matter how many things go wonky:

"Avoid drowning, embolism, and the bends -- in that order."​

 

[johndiver999]

I did some experimenting several years after I started diving to figure out how much weight I could drop and reasonably control my ascent rate. Keep in mind that the maximum ascent rate was 60' or 18M per minute then. I tied about 50'/15M of line from my weight belt to a surface float.

I was using a pretty heavy wetsuit with 3 layers that require about 25 Lbs/7.6 Kg to reach neutral at 10'/3M. I transferred about half the weight to a second belt that I didn't drop and started testing. I moved about 2 Lbs/1Kg to the belt I dropped for each test. I found I could drop 22 Lbs/10 Kg before I got uncomfortable controlling the ascent. YMMV.

I used the data from that exercise ever since, but more important is the self-confidence and "feathering" techniques to slow ascent. I have never had to drop lead, but knowing that I can and what it feels like eliminates any apprehension to dump lead. It really doesn't matter that the current ascent rate is half as fast, safety stops are recommended (not required), or you even have a small decompression obligation. The important part is to have a reflexive plan that addresses these priorities, not matter how many things go wonky:

"Avoid drowning, embolism, and the bends -- in that order."​

This is very useful and instructive. Actual hard data that applies to a particular situation, one of the more challenging ones..

Question: When you say feathering what does that mean in practice?

 

[Akimbo]

Question: When you say feathering what does that mean in practice?

Feathering can range from going horizontal and spread-eagle to increase your hydrodynamic resistance to actively finning toward the bottom. Swimming head-down as you ascend against buoyancy would be an extreme case. I was comfortable swimming head-down at about 30° at a moderate rate.

Keep in mind that dropping weight isn't the only time you could accidentally find yourself in a very buoyant emergency. Accidental entanglement in a larger DSMB or lift bag, a BC malfunction, or helping a panicked buddy can happen. The problem is you won't have time to analyze the situation before you are floating on the surface, and possibly bent or embolized. Exhaling and resisting the ascent has to be a reflex and this type of controlled exercise is helpful in developing it.

Just remember, exhale and take baby steps adding buoyancy when performing this exercise! Do NOT use air in your BC instead of dropping weight.

 

[Sam Miller III]

As was often stated in the genesis of diving

"Better no lead than dead...
Blow and go...
Flair and you are there... "

I will take my chances with a droppable disposable weight belt
and if necessary at chamber ride for DCS or barotrauma

SDM