11:45 p.m. The wind picks up, so I descend to the boat's underwater viewing chamber. The sounds of waves make for a surreal soundstage. "This is my favorite time to be here," says Mel. I try to converse with her while locked in a staring contest with a 1,500-pound Queensland grouper named George. We're separated by a thin plane of glass 10 feet beneath the surface of the Coral Sea. Flashes of silver explode through the background: giant trevally in search of a midnight snack. George floats there, keeping one giant eye suspiciously trained on me. He wins because exhaustion finds me. It's well past midnight. I can't wait for sunrise, when I can jump all the way in.