Yes, the reason weights are needed are to allow neutral buoyancy. You should already know this. The air buddy uses an air hose full of air. Air is buoyant. Weights are used to counteract the buoyancy of the air hose and other buoyant concerns. Its basic Archimedes Principle. My guess is that the air hose would need to weighted to do a buoyancy check to determined how much weight a diver needs to be neutral.
https://www.idc-guide.com/physics/
Bill
I'm afraid you still haven't understood my point, so I'll try one last time:
The model in this video isn't wearing a BCD, but is wearing weights. Someone else pointed out that weights are needed to achieve neutral buoyancy, and of course I understand that, however, that neutral buoyancy is dependent on a number of factors, and the factor I'm trying to point out is
DEPTH.
The model is kneeling at the bottom and thus neutrally buoyant, we think. It is possible that she is negative buoyant, but we don't know that. For this discussion let's assume she's neutrally buoyant.
Now, when she ascends 10 feet, will she still be neutrally buoyant Bill? And if the coils in her tether allowed her to descend another 10 meters, would she then also still be neutrally buoyant?
Oh, and thanks for the dive lesson. From someone that considers this divebuddy
scuba, I hope you won't be offended if I rely on the training I received elsewhere
Have fun blowing bubbles everyone!! Be safe.