In an essay on the rationality of play, the author characterizes rationality by the three distinct demands it makes on the individual--demands for autonomy, solidarity, and integrity. He develops each of these as they apply to the sport of sailing, using the example of two deep-ocean expeditions to arrive at a concept of deep play he sees as one solution to the existential problem of living rationally. In the course of doing so, he suggests why so many disparate activities fall under this concept of deep play and concludes with a reflection on how deep play transcends sports.