The Loxahatchee River and estuary is a small (544 square miles), shallow, water body located in Southeastern Florida that empties into the Atlantic Ocean at Jupiter Inlet. The watershed drains an area of over 200 square miles within northern Palm Beach and southern Martin counties. Historically this system was primarily fresh-water; however, tidal flows opened the inlet for some of the time. In 1947, the inlet was dredged for navigation and has remained permanently open since that time. Drainage patterns within the basin have been significantly altered due to drainage and development, road construction (e.g., Florida Turnpike, BeeLine Highway), and construction of the C-18 canal to provide flood protection for residential areas. The St. Lucie Estuary (SLE) and its watershed are located on the Southeast coast of Florida in Martin and St. Lucie counties. The SLE watershed encompasses about 781 square miles and is divided into five major basins, which discharge into the Indian River Lagoon and the Atlantic Ocean through the St. Lucie Inlet. The St. Lucie Canal (C-44), along with the Caloosahatchee River (C-43) are important components of the Central and Southern Florida Project and are primarily used for water releases from Lake Okeechobee when lake levels exceed established regulatory requirements of the United States Army Corps of Engineers. The C-44 Basin is particularly dependent on the lake for supplemental water supply and aquifer recharge. This report serves as an archive of processed single-beam bathymetry data that were collected in Loxahatcheee and St. Lucie Rivers, Florida in 2003. Geographic information system data products include a XYZ data, bathymetric contours, and USGS quadrangle map. Additional files include formal Federal Geographic Data Committee metadata.