Metallic components and equipment for service in the marine power generation and process industries are commonly exposed to halide-bearing waters and brines. These media especially when hot can be very agressive. While highly alloyed NiCrMo products generally provide resistance by understanding the true nature of the corrodents more economical materials can often be successfully used. This paper looks at the performance of super-austenitic stainless steels and FeNiCrMo and NiCrMo alloysin various halide environments to determine the conditions under which the various materials will perform and when more highly alloyed materials are really needed for resistance. Several media are examined including sodium potassium calcium and magenesium salts as well as seawater. The effect of chlorination is also explored. As might be expected temperature has a siginificant effect on performance.