The Problem with Metals For as long as man has worked in the sea, implements and structures have been produced for use in this unusual environment. Early equipment was produced in iron, and later from steel. However, a problem soon became apparent. Seawater is a highly corrosive medium in which these materials rust very quickly. Corrosion of metals, and in particular carbon steels, remains a serious problem to this day.
Solutions are available.
Items can be coated with materials, such as paint, which provide a barrier to attack from the surrounding seawater. However, coatings of this type are easily damaged during handling, so this may not be a solution to long-term exposure. An alternative method regularly used in conjunction with barrier coatings is the use of cathodic protection. Here, the component in question is fitted with anodes, normally in the form of blocks of metallic alloys. Sacrificial corrosion of the anodes provides a form of electrical protection.