For better or worse, Rosemary Mahoney will forever be remembered for "Whoredom in Kimmage," her 1994 study of sex and gender in Ireland. Mahoney's latest book "Down the Nile: Alone in a Fisherman's Skiff" is quite different, though not entirely. Mahoney has long been an avid rower, and the book began when she set out to purchase an Egyptian rowboat and sail the ancient river, the world's longest. For this reader, an account of someone floating down a river seemed less than fascinating. However, when your guide is as learned, humorous and observant as Mahoney, the trip becomes a worthwhile one. So, how is this similar to "Whoredom in Kimmage"? Well, it turns out even a simple ride down a river can be loaded with cultural questions related to sex and gender and culture. Suffice it to say a lone Western woman rowing herself down the Nile is not a sight to which Egyptians are accustomed. Mahoney is forced to confront and navigate numerous cultural questions that are nearly as troubling as the crocodiles in the Nile. ($23.99 / 288 pages / Little, Brown)