Internal cathodic protection by resistor controlled anodes - Resistor controlled Cathodic Protection(RCP) - was introduced in 1991 as an alternative method for the prevention of localized corrosion of seawater transportation systems. More than five hundred RCP andodes have been installed in seawater piping systems made from highly alloyed stainless steel which had suffered from corrosion. This paper desribes some of the installations including experiences so far. In addition the possible use of AISI 316L combined with RCP anodes is described.