Flotsametrics and the Floating World: How one man's obsession with runaway sneakers and rubber ducks revolutionized ocean science by Curtis Ebbesmeyer

This is a wonderful book about everything that floats in the ocean and why it goes where it does and how fast. There are circular currents, beaches that collect debris, and large areas of ocean choked with plastic. By tracking ordinary flotsam, Ebbesmeyer has made the ocean currents give up many of their secrets. He weaves history, science, and beachcombing into a fascinating tale. He writes with the confident but understated tone of someone who really knows what he is writing about.