Question about “balanced rigs” and having all ballast unditchable

[Trace Malinowski]

I've encountered recreational divers who don't need any weight whatsoever in a single tank rig using weights just so they have something to ditch. They are already overweighted by having a muscle/bone/fat ratio that allows them to dive without requiring added ballast then they are intentionally overweighted just so they have weights to ditch in an emergency. Sadly, when I've politely asked them how that reasoning makes sense, the response has been, "Because our instructor said we needed ditchable weights." I'm hoping in such cases there was a miscommunication between the instructor and the students where the instructor just wanted them to have weights to ditch during emergency ascent skill practice so they'd understand how the procedure was supposed to work if they found themselves wearing weight in the future.

 

[Akimbo]

They are already overweighted by having a muscle/bone/fat ratio that allows them to dive without requiring added ballast ...

I concur with your overall message but the ratio of fat and muscle is not a major variable in buoyancy. The specific gravity of muscle is about 1.06 verses about 0.9 for fat (fresh water is 1.0). For all practical purposes, the ratio of lung capacity to bone weight is the is the major factor; excluding the morbidly obese.

In my case, I was neutral in a swimming pool with a mid-normal lung full of air in my mid-20s. I am now about 3 Kg/6.6 Lbs positive. My measured lung capacity is a 5% higher, but that could be tolerance in the methodology. My weight is about the same and, no doubt, my fat to muscle ratio is now more fat, but I was concerned so asked for a bone scan. Sure enough, I do have osteopenia, not bad enough to treat yet but will likely progress towards osteoporosis if nothing else take me out first.

 

[Dan]

My answer is that it is a Doing it Right (DIR) term. "Balanced Rig" is a term that was probably coined by George Irvine. It has been continued by GUE as the President Jarrod Jablonski was also on the WKPP exploration with George. Equipment Configuration | Global Underwater Explorers

If you watch the video below it is still pretty relevent today (unless you despise DIR). In the video keep in mind that dive computers were closer to their infancy and weren't yet trusted but the rest is still relevant in my opinion.

What would dive computer help to having a "balanced rig"

 

[Eric Sedletzky]

I've encountered recreational divers who don't need any weight whatsoever in a single tank rig using weights just so they have something to ditch. They are already overweighted by having a muscle/bone/fat ratio that allows them to dive without requiring added ballast then they are intentionally overweighted just so they have weights to ditch in an emergency. Sadly, when I've politely asked them how that reasoning makes sense, the response has been, "Because our instructor said we needed ditchable weights." I'm hoping in such cases there was a miscommunication between the instructor and the students where the instructor just wanted them to have weights to ditch during emergency ascent skill practice so they'd understand how the procedure was supposed to work if they found themselves wearing weight in the future.

Proper weighting should be the number one priority, after that people can break up their weights in any fashion they want. If someone is diving in water warm enough not to need any exposure protection and their scuba unit alone provides enough balast to dive normal then leave it. Adding weights to that is silly.
I used to experiment in a pool with a steel 72 strapped to my back, no BC or plate, just the tank on my bare back in a basket harness, board shorts, MK2 with one second stage. I could hold any depth perfectly, including staying at the surface no problem. I was obviously low in the water but as long as I could get air that’s all I cared about. I thought that was pretty neat, I was imagining doing that somewhere warm in a tropical ocean.
Adding unecessary weight and a BC to offset it would have just added more crap and made me into another elevator diver highly dependent on an aircell for support . I don’t do things that way.

 

[Trace Malinowski]

What would dive computer help to having a "balanced rig"

The human brain. It weighs about 3 lbs. on land or 2% of body weight if you are in shape.

 

[EireDiver606]

A balanced rig is a system that allows you to swim up to the surface in the case of a failed wing and at the end of your dive, hold your decompression stop at 3m with nearly empty tanks.

 

[tomfcrist]

99.999% of the time, I’m overweighted. That’s with a kydex backplate, no added lead...any tank configuration. Why would I wear ditchable weight? Even better question, why do you care if someone wears ditchable weight or not?

Technically, on most dives, I have ditchable weight...deco/bailout bottles..can light, reels etc. but if I was really concerned about getting positive at the surface..I guess I’d just ditch the whole rig...takes about 2 seconds longer than ditching a weightbelt.

 

[EireDiver606]

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.

I was taught that you should never need to remove your rig at depth.

This was told to me by my instructor who has over 4000 dives and has dived all over the world.

I’m not trying to be rude but how would you get a kelp entanglement? You shouldn’t be swimming near kelp or marine life....

 

[EireDiver606]

OK. This question gave me serious pause. I'm not so sure that no ditchable weight ever did become a 'thing'!

I put some thought into this. I think that maybe you are expecting a common theme for both singles and doubles. Such does not exist. It is damn hard to make a balanced coldwater doubles drysuit rig. Singles, no prob.

Maybe read this for insight: Balanced Rig with a Single Tank?

-or I could be totally off-base on this. Even if so, it is a most interesting question.

It depends on size and pressure for the doubles?

 

[Trace Malinowski]

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.

I was taught that you should never need to remove your rig at depth.

This was told to me by my instructor who has over 4000 dives and has dived all over the world.

I’m not trying to be rude but how would you get a kelp entanglement? You shouldn’t be swimming near kelp or marine life....