Near the end of Tony Horwitz's latest book, an Alaskan archaeologist speculates that "prehistoric people who trekked out of Africa may have relied on intrepid, nervy individuals to lead the journey." Those people may, in fact, have been genetically different: they wanted to find things, people, and places no one else had ever seen before. A former Wall Street Journal reporter and New Yorker staff writer, Horwitz has written about Australia (One for the Road, 1988), the Middle East (Baghdad without a Map, 1991), and the American South (Confederates in the Attic, 1999). If restlessness is congenital, Horwitz has a serious case.

In Blue Latitudes he again takes to the road (or the sea, in this case), to follow the wake of Captain James Cook - arguably the greatest explorer and mapmaker in history. After a short stint as a deckhand on a modern replica of the Endeavour, the ship on which Cook did the first of his three circumnavigations, Horwitz then travels by more modern means to Tahiti, Australia, Unalaska, and Hawaii, among other places. He skips Antarctica, he writes, "because I like adventures where I encounter people, not penguins."

In 1768, when Cook set sail on his first voyage, "roughly a third of the world's map remained blank," Horwitz writes. Over the next eleven years, Cook would see more of the planet than anyone before him. During his first and second trips, while searching for the great southern continent theorized by European geographers to "balance" the landmass in the northern hemisphere, Cook became the first European to lay eyes on New Zealand, Tonga, and a number of other South Pacific island chains. During his third trip, a failed attempt to find a northern passage around the Americas, he became the first white visitor to Hawaii and the west coasts of what are now Canada and Alaska. (The Russians had beaten him to the Aleutian Islands.)

A lone traveler in his previous books, Horwitz adds a sidekick for much of Blue Latitudes. Roger Williamson is a semialcoholic, recently divorced Australian who is on the lookout for "crumpet. Warm, willing flesh." When Horwitz asks him along to Tahiti, Williamson takes to the idea: "We'll put on wigs and stockings and march onto the beach. Of course, Cook didn't disgrace himself by rooting the natives, only filthy sailors did that. They were tough as boots. You can play Cook."

When the two visit Niue (pronounced new-way), about 750 miles east of Fiji, Williamson unwittingly insults an islander with "loud and rather lewd praise" of two women he'd met (the man's daughter and niece), and then accidentally steals the police minister's car and drives it home in a stupor. The visit probably did little to salve the wounds opened by Cook some 230 years before. He named the place Savage Island after natives greeted his landing party with a hailstorm of spears and rocks, their teeth and lips smeared with the juice of red bananas. At a meeting of the island's London Missionary Society, a minister tells Horwitz: "Cook called Tonga the Friendly Isles, probably because he had so many girls there. Tahiti he called the Society Isles, same reason. Nice names. But because we throw a few stones and spears, we're savages. No one likes Cook much in Niue."