Cathodic protection is the protection of a metal object (cathode) against corrosion by connecting it to a less noble metal (anode) in the same electrolyte.
When the current needed for the protection process is delivered by the anode metal itself. In this case, so-called active sacrificial anode types are used. These anodes are manufactured from metals less noble than steel, such as magnesium, aluminum, and zinc. The anode material corrodes while delivering current.
Sacrificial anodes can be used in a high saline environment.