Terminology: RV Depth? Fail Depth?

[Jeroen Elout]

Hello Divers, I wonder what wording you use for the following:

1. The Depth your Lungs reach Residual Volume. RV Depth? or Sqeeze depth? or different?

2.The Max Depth your Lungs can stand without injury. Is that Max Lung Depth? Fail Depth or different?

 

[Wildor]

The depth at which your lungs reach residual volume (RV) is called failure depth because it is the depth at which standard frenzel or valsalva equalization usually fails (since you cant bring up air from the lungs without reverse packing or doing mouthfill before RV).
I have not heard of any term applied to the depth your lungs can stand without injury. The depth is going to vary with training and technique. But also lung injury is not necessarily due to depth but can have to do with for instance aggressive equalization, lack of relaxation, and the way one moves.