I do a lot of cave and wreck diving, where box breathing is reguarly touted as a fantastic way to calm yourself if you get into a stressful situation. You do it

I do a lot of cave and wreck diving, where box breathing is reguarly touted as a fantastic way to calm yourself if you get into a stressful situation. You do it while at rest if you find yourself disorientated. Never hold your breate while ascending =/= Never hold your breathe underwater.