Four hydrographic surveys were performed on May 28, 2004, along an east-to-west transect up the Altamaha River in Georgia (Altamaha River Transect, GCE-AL). Vertical CTD profiles were collected at 2km intervals from -4km to 24km upriver along the transect during low and high tidal regimes. Conductivity, temperature, pressure and optical backscatter were measured, and depth, salinity and sigma-t were calculated for each profile. Data values collected on the upcast were deleted, and the remaining data were averaged within 0.5m depth bins and interpolated to produce a smooth profile for contouring. This data set was collected as part of the Georgia Coastal Ecosystems LTER quarterly hydrographic monitoring program.