The Shark Shield generates an electrical field that is detected by the shark through its sensory receptors, known as the Ampullae of Lorenzini, found on the snouts of many sharks. Once detected by the sharks' sensors, the field causes muscular spasms that result in the shark being deterred from the area.
The field is projected from the unit by two electrodes, which create an elliptical field that surrounds the user. Both electrodes must be immersed in the water for the field to be created.