a method and device for facilitating maintenance of an anode of a marine engine cooling system , the device including an anode for use with an anode plug such as , for example , an anode plug that has a detachable component with a threaded end for mounting to a threaded bore of a cooling system structure , and a connector that holds the anode , the anode having an indicator for indicating a condition of the anode which is indicative of a need to replace the anode the method permits changing the anode by removing and / or reinstalling an anode while preventing or minimizing water from exiting the cooling system of the marine engine .