A readable biography of the man who was scarcely out of his teens before he had written the authoritative book on navigation still used at Annapolis takes Nathaniel Bowditch from a childhood in Salem through a good part of a successful seafaring career. Though Nat was apprenticed to a ships' chandler when he was twelve and was of slight stature, these two drawbacks only served to spur him on. He read Latin and Newton at night. When his apprenticeship was finished he went to sea and began astounding captains with an extraordinary navigation ability that got their ships out of stringent circumstances,- a monsoon in Manila and a three day fog outside of Salem. While the drama of these events is the main substance of the book, some profitable attention is paid to Nat's methods of studying, his conviction that he could explain navigation clearly, and the important principles he followed.