This study was funded by the Municipio de Rincón. The authors thank the Mayor of Rincón, the Honorable Carlos D. Lopez Bonilla, his staff, and members of the community for their support. Thanks also are extended to Barry Irwin (USGS), Bill Danforth (USGS), and Milton Carlo (University of Puerto Rico) for field assistance during the GPS surveys and in the processing of shoreline and bathymetry data and to Marilyn Santiago (USGS) for providing orthophotography and related cartographic information. Kathryn Scanlon, Cheryl Hapke, Jeffress Williams, and Anne Finch are thanked for technical and editorial comments on the report.