We swim in freezing Arctic waters and piranha-infested rivers to test our limits. We swim for pleasure, for exercise, for healing. But humans, unlike other animals that are drawn to water, are not natural-born swimmers. We must be taught. Our evolutionary ancestors learned for survival; now, in the twenty-first century, swimming is one of the most popular activities in the world. Why We Swim is propelled by stories of Olympic champions, a Baghdad swim club that meets in Saddam Hussein's palace pool, modern-day Japanese samurai swimmers, and even an Icelandic fisherman who improbably survives a wintry six-hour swim after a shipwreck. New York Times contributor Bonnie Tsui, a swimmer herself, dives into the deep, from the San Francisco Bay to the South China Sea, investigating what it is about water that seduces us, despite its dangers, and why we come back to it again and again.