Somewhere amid the ebbs and eddies of a curious childhood I wondered who Alexander von Humboldt might be. I had noticed all the places named for him, sprinkled on maps of the world, and assumed he was some kind of explorer. It was not till I took up sailing in my late twenties that I learned of the Humboldt Current, a cold nutrient-rich Pacific current known to fishermen from time immemorial, that runs up the coast of South America from Chile to Peru, Ecuador and Columbia.