“Anti-what”? Antifouling, a term well known by sailors who think of the paint of the same name applied to the boat hulls and intended to prevent aquatic organisms from attaching to them.
Fouling being a natural phenomenon, it is necessary to protect submerged objects such as ship hulls, but also certain installations of oil platforms, ports, nuclear power plants (heat exchangers cooled by sea water for example) …
For this application, cupronickel was chosen for its ability to resist the proliferation of aquatic organisms on its surface, which is not the case with stainless steels and standard duplexes
Cupronickel is thus widely used in marine environments