Although the theme is fly fishing, this book is really about the more esoteric, spiritual aspects of fishing. Through his poetry, essays, and short fiction, Delp writes about being haunted by fishing, about being taken over, literally, by the desire to fish and spend time alone on trout streams. He describes the experience as "a pause, a deep breath in the crush of living. It seems incredibly simple, yet trout fishing illuminates an inner life, asks the mind and body to give themselves over to another power: Under the Influence of Water is about moments-how time goes away on a river. It's about waking up and finding out that what runs in your veins is river water mixed with blood. It's also about trying to find the courage to one day stand in a river and admit your life. Delp says that's what happens when you fly fish . . . you get your life back, if only for a few moments. When you go back to your other life, the river is still with you. Ifit's not, then you haven't really been on a river.