The system uses an on board electronic control unit, with a reference anode and an active anode - both fitted below the waterline. The reference anode senses the electrical potential of the surrounding water and sends a signal to the control unit, which in turn sends an appropriate current to the active anode. Different combinations of water temperature, chemical composition and exposed surface require different levels of current. The active anode then emits varying levels of ions into the water surrounding the drive, and these ions effectively prevent galvanic corrosion, ultimately protecting the drive.