Stephen P. Leatherman, professor and director of the Laboratory for Coastal Research at Florida International University, earned his nickname. Since developing no less than 50 criteria for evaluating beach quality 20 years ago, "Dr. Beach" has been rating shorelines all over the world. What factors does he consider when determining a beach's worthiness? Water temperature, safety, and weather are all incredibly important, but he maintains that the most important single factor is water quality. "That’s the first thing people really ask for," he says, adding that Americans are fortunate because "most of our beaches in the United States are in very good shape."\r\nWe asked Leatherman were to go to get wet and he picked out the best beaches for swimmers in the country. Just remember to bring your floaties with you.