It could be one of the most incredible, yet perplexing, survival stories of all time: In 1991, a man named Michael Proudfoot was supposedly SCUBA diving on a shipwreck off the coast of Baja, Mexico, when his regulator—or mouthpiece—broke. He was alone, deep underwater inside a sunken ship, with only minutes to survive before he would run out of air. The string of bizarre events that take place next seem unreal.