A cruising aerator includes a raft, a motor mounted on the raft, a shaft driven by the motor, a first impeller mounted on the shaft, a second impeller mounted on the shaft, and a common chamber. The cruising aerator further includes a sequential controller connected to the motor for controlling the motor to rotate clockwise or counterclockwise. The motor, the shaft and impellers are installed inside of the common chamber. The common chamber has a common inlet disposed under a water surface. A first outlet and a second outlet of the common chamber are arranged to face in opposite directions. The first impeller and second impeller are assembled to have opposite normal rotating directions to each other according to a rotating direction of the motor.