The chloride-ion contents of more than 700 sea water samples from the coastal waters of western Louisiana were converted to salinity values and were used in a study of the salinity characteristics. These data were gathered from seven drilling platforms during a period of 14 months in a zone paralleling the coast for about 60 miles, approximately 6 to 8 miles offshore and in depths varying between 40 and 50 feet. The chloride-ion content was determined by the standard chemical titration method in connection with quality control of salt water drilling mud used in the drilling of offshore oil wells....