Name one example of a such scenario where it'd be needed to ditch weight when in a balanced rig, please.
A big, muscular, low body fat diver in a thick wetsuit using aluminum doubles, with a bcd failure at depth, and no redundant buoyancy.
That's not a balanced rig, then.
Generally, thick wetsuits at depth aren't, due to the bouyancy swing brought about by compression of the thick neoprene.
But, we're aiming for thermal protection here, right? A thick wetsuit that's heavily compressed is really just a thin wetsuit, and not the intended thermal protection anyway.
A big, muscular, low body fat diver using aluminum doubles with a drysuit failure, but only carrying a 50# wing, say.
If the wing isn't big enough to carry the diver, it's not a balanced rig.
But if we're looking at a - say - 21L wing, how is that not enough for two ali tanks?
The mistakes in both scenarios are obvious: absent or inadequate redundant buoyancy. However the sheer length of time this thread has been active shows why the OP's question is relevant.
I agree that the issue is lack of redundant bouyancy in both cases. A drysuit would do the trick.
And I agree that my view on ditchable weight should be seen in light of prerequisiting the rig is balanced.
OK, you have a medical problem and your buddy needs to get you in the boat when seconds count.
From the surface, you need to get them out of a rig in either case. With ditchable lead, that's just one more thing to do.
From submerged, I wouldn't send an unconscious diver on an uncontrolled ascent on their own.
Surfacing OOG in a bit of chop, and the pickup not being nearby. Maybe even out of sight. Particularly if you also are of the the "no snorkel" school.
Me, I'd love to float some 5-8kg higher in the water in a situation like that. A few years ago, someone died up here because the wind had freshened while she was below, and she wasn't able to avoid breathing water as the waves broke over her.
Orally inflate the wing while using the donor's regulator.
Standard OOG training scenario, every time.
I do agree in that I also prefer to float comfortably. But that's separate from a question on ditchable weight.
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Conversely, we see these reports about divers drowning because they "didn't drop their weight belt".
Risking AGE.
Risking DCS.
Risking surface traffic.
Balanced Rig is a universally applicable solution to the weighting/redundancy question, that's where it comes from and that's why it's used.
On a personal note entirely, I don't even bother selling jacket-style BCDs.
I see jacket-style BCDs in a contemporary setting as a marketing gimmick on par with split-fins, spare airs and those silly little rape-whistles people keep dragging along;
"Hold on, crack the window, I think I hear something"
- No rescue helicopter pilot, ever
