This set of CTD measurements places the fresh water discharge into the sea, which is located in Punta Esmeralda in the City of Playa del Carmen, State of Quintana Roo, in the Mexican Caribbean Sea. For these measurements two measuring instruments were used; a CTD for temperature and salinity profiles and a USGS type AA current meter to measure discharge to the sea, applying two methodologies for the measurement of volumetric flow according to FAO, (2009). Punta Esmeralda is a beach site that has three springs on the beach which form a freshwater lagoon about 60 meters long by 25 wide and a deep part of 1.6 meters. This lagoon is located at the coordinates 20.648372 ° N 87.050909 ° W. The discharge of water forms a small stream with a stream 6 meters wide with a bathymetric profile with a maximum depth of 0.40 m. These dimensions change over time due to natural and artificial processes. The fresh water discharge to the sea has an average flow of 0.2142 m³ /s , at an average speed of 0.1305 m /s. The sampling points with the CTD were a total of 61 and were distributed throughout the lagoon, the output of the three largest springs and a small "cenote" that is located about 76 meters away from the beach, were also performed sampling points in the sea at a distance of 100 meters from the coast and 2 meters deep. The salinity ranges measured in the springs was 4 UPS and it was increasing to the sea with 35 UPS. With temperatures in the springs from 25.8 ° C to 30.8 ° C in the sea.