** FOR USE WITH AP SPECIAL EDITIONS SUMMER ** Tubers float on the Comal River in New Braunfels, Texas, Thursday, May 27, 2004. While float tubing can still be enjoyed by anyone with an old inner tube at a favorite swimming hole, river concessions around the country now offer equipment, shuttle service, changing rooms and more, looking to bring families out for a day on the nation's most scenic rivers. (AP Photo/Eric Gay)