Party Animals

Hanging from the top edge is deep enough. I unlocked this by jumping across the opening so I could grab the edge and immediately climb out. I think if you go any deeper, you won't have time to make the climb before the gate closes. I tried that too, but got my head closed in the gate. I was still alive for a bit, so I might have been able to get out if a teammate had opened the gate again. But it's not necessary.