It’s hard, because none of us have experienced it, but try to imagine it. Your boat is upturned, most of it is full of water; you’re huddled into a small space in the forepeak. You’re wondering what will come first; will your air supply run out, will the boat sink and take you with it, or will you be rescued.
Imagine then the relief when you hear a fog horn and set off your second EPIRB, to tell the world you are alive. You think rescue is imminent, but it doesn’t happen, because what you don’t know and it can’t tell you is that the giant tanker can see your upturned boat, but cannot launch its boat in the 5 meter waves. Imagine your feeling of desolation, when the salvation you hoped for doesn’t happen.