An apparatus for aerating bodies of water includes a floating platform, a motor supported by the floating platform, a transmission which is coupled to the motor and whose output shaft is in the form of a hollow shaft, a fan for supplying air through an air supply line connected thereto, wherein the air supply line is connected to one end of the hollow shaft, a hollow stirring shaft coupled to the other end of the hollow shaft, an stirrer affixed to the free end of the approximately vertical stirring shaft, wherein the stirrer is designated as a hollow body and has a central opening through which air supplied by the stirring shaft can pass, and a multiplicity of air outlet openings.