The U.S. Navy and others utilize both zinc and aluminum sacrificial anodes for galvanic cathodic protection of marine ships and structures. However, with the proliferating usage of impressed current cathodic protection systems for ship hulls, usage of these has been limited to interior spaces and difficult regions to protect with ICCP. Cathodic protection in these latter spaces is sometimes complicated by the
presence of high strength alloys which are particularly susceptible to stress corrosion cracking (SCC) or hydrogen embrittlement and the cathodic potentials resulting from galvanic coupling to either zinc or
aluminum alloy (Al/Zn/Hg or Al/Zn/In) galvanic anodes increase the susceptibility. Due to similar concerns, the French Navy has pursued the development of a low-voltage Al-0.1%Ga galvanic anode for use in galvanic cathodic protection of high strength steels. Recently, this Al-0.1%Ga alloy was tested at full scale at the Naval Research Laboratory Anode Qualification Site in Key West, FL. Results regarding the working potential and current capacity of this alloy in natural seawater are presented in the following.