A device comprising an electrically conductive surface portion is provided for immersion in an electrically conductive liquid such as water. At least one load electrode is provided for supplying an electric load current into the electrically conductive liquid. Further, an electrode, e.g., one or more of the at least one load electrode acts as protection electrode. A protection current source, e.g., a resistor, is electrically coupled to the conductive surface portion and to the protection electrode for providing a protection current flowing between the electrically conductive surface portion and the electrode. Further, the protection current source is adapted for changing the protection current in response to a change in the load current.