Funding for this project was provided by the Coastal Services Center of the National Oceanic and Atmospheric Administration and the U.S. Geological Survey Coastal and Marine Geology Program. We acknowledge the field support provided by E. Bergeron, B. Danforth, J. Denny, B. Irwin, and C. Worley of the U.S. Geological Survey Seafloor Mapping Group in Woods Hole, Mass.; L. Edmiston, S. Fahrny, M. Lamb, L. Levi, and J. Wanat of the Florida Deptartment of Environmental Protection in Apalachicola, Fla., and D. Bennett, J. Bernier, N. Ferina, and J. Sanford of the U.S. Geological Survey in St. Petersburg, Fla. The report benefited from reviews by Katherine McMullen, Matthew Arsenault, and Elizabeth Pendleton.