Biographer Niven uses her later-in-life swim training as a metaphor to structure this affectionate, if sometimes unfocused, rulebook for living.""As I found myself middle-aged and simultaneously being outfitted with braces and bifocals,"" she writes,""it came to me that I had nothing to lose"" by learning to swim. Starting from simply getting into the water--one can jump in feet first, dive headlong or tentatively slide in, she notes--and moving on to floating, swim strokes and, finally, swimming alone and in the ocean, the author discovered that modern life and swimming hold parallel lessons. Nivens interweaves her newfound wisdom with words from her favorite writers and biographical subjects (Carl Sandburg, Thorton Wilder), her upbringing in tiny Waxhaw, North Carolina, and her subsequent years as a wife, mother, divorcee and writer who only signed her first book contract in her 40s. Since overcoming her anxieties about water led her to simultaneously dive into her dream of writing, she includes intriguing writing prompts following each chapter. Many of her anecdotes are enjoyable reading, such as her parents' hospital bed feud over whether to be cremated or buried, or Aunt Geneva Walkup Rone's belief in a world map that contains only four places:""Heaven. Hell. Waxhaw. And Off Somewhere."" Niven is occasionally over-jubilant in celebrating her daughter's insights or her father's dignity and good humor; a few well-chosen quotes would do better than the constant adoration. Still, the book, like Niven's preferred backstroke,""forces the vision upward"" and will inspire readers. With b&w illustrations.