This U.S. Geological Survey (USGS) Data Release provides spatial water-quality data collected from the Caloosahatchee River and St. Lucie River July 13-15, 2020 and the Caloosahatchee River September 22 and 23 of 2019, south Florida. The St. Lucie portion of the surveys was not able to be completed in September due to boat engine failure. Geo-referenced measurements of near surface water temperature, specific conductance, dissolved oxygen, pH, turbidity, chlorophyll fluorescence, phycocyanin fluorescence, and fluorescence of dissolved organic matter were recorded at 20 second intervals and nitrate+nitrite as nitrogen was recorded at 5 to 60 second intervals during water-quality surveys in order to create high resolution water-quality maps of the study area.