Distribution of salinity, dissolved oxygen, nitrate, phosphate, and silicate are presented for the western Gulf of Mexico in 1978. Plots of chemical concentration versus potential density are used to identify the presence of gulf water, tropical Atlantic central water. Antarctic intermediate water, Caribbean midwater, and upper North Atlantic deep water within the upper 1600 m of the western Gulf of Mexico. Property distributions are closely related to the current regime described by Merrell and Morrison (1981). Also, we present values for tritium, carbon 14, radium 226, and radon 222 that were taken at a deep station located at 23¿02'N and 92¿28'W.