Described is a chondrichthyan repelling system comprising at least one fin comprising at least one electrically conductive electrode for connection to an electrical signal generator. In use, the electrical signal generator generates electrical signals to the at least one electrode to thereby radiate an electrical field which repels chondrichthyans. Also disclosed are various fin designs incorporating one or more electrodes, and a watercraft having one or more fins as described. Various means of connecting the electrodes to the electrical signal generator are also described.