The immersed metal structures on which cathodic protection can be applied are mobile (mobile boats, tankers, platforms, lock gates, etc.) or fixed (harbour works, offshore underwater platforms and installations, beacons, immersed pipes, floating storages, etc). They are in sea water or in fresh or brackish waters. Almost all these structures have a protection coating, except the fixed platforms.
Cathodic protection is now systematically applied to tankers and metal boats, as well as to offshore platforms and the immersed pipes.