The Use of Magnesium for the External Cathodic Protection of Marine Vessels^✫

Reports are made on the use of magnesium anodes for the external cathodic protection of marine vessels. Experimental studies over a 5-year interval reveal that the over-all hull, in addition to the much-discussed stern area, may be protected effectively by a distributed system of anodes. The variables of anode weight, optimum length and number of anode strings are related to a one or two-year anode life. Absence of marine fouling over the same period is discussed. Some consideration is given to economic matters. Cost data for cathodic protection of ships is given and compared with maintenance costs for unprotected ships. 8.9.5