A shark repellent system for repelling sharks away from an individual while boating. The shark repellent system includes an attachable magnet and a transmitter unit that emits sound waves at a frequency undesirable to sharks. The transmitter unit is contained in a watertight enclosure affixed to a buoyant device, and is usually submerged in water while the buoyant device is in the water. The magnet may function as an on/off switch for the transmitter unit. The transmitter unit may also be positioned within the boat or other buoyant device, wherein the transmitter unit includes a plurality of transducers electrically connected to the transmitter unit via elongated cables and the cables and transmitter units are extended over the sides of the boat. The transmitter unit may also include a standard toggle switch and/or a water sensor to turn the transmitter unit and thus transducers on/off.