TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The vortex control plate has holes. It may be a grill. A forced air source delivers forced air proximate to the first propeller. The drive shaft is a tubular drive shaft and the forced air source is connected with the drive shaft. The forced air source is adjustable to control the forced air delivered. It is selectively operable independently of the power source. The power source rotates the drive shaft at 700-1000 RPM (preferably 700-800 or 750-950 RPM). A second propeller is disposed on the drive shaft. The first propeller is larger than the second propeller. It is mounted between the second propeller and the power source. An atomizer comprising flat or curved blades is disposed at the second end of the drive shaft. The tubular drive shaft has a lumen with an open end proximate to the second end of the drive shaft and the blades extend radially outward over the open end of the lumen. A radial extent of the second propeller is greater than a radial extent of the blades of the atomizer. The apparatus includes a frame having mounting brackets for mounting the power source and floats mounted to the frame. The frame levels with respect to a water surface during operation. Alternatively, the fluid agitation apparatus comprises a tubular drive shaft (126) having a first end coupled to a selectively rotatable power source and a second end, a forced air source (110) connected to the drive shaft, a first propeller coupled to the drive shaft, a second propeller coupled to the drive shaft, and an aspirator disposed at an end of the drive shaft. The power source is operable at 700-1000 RPM. The first propeller is sized to create an optimal fluid flow at 700-1000 RPM. A submergible vortex shield (128) is disposed over the first propeller. The vortex shield is flat or curved. It has a surface provided with holes. The apparatus may include an electric 8-pole motor (122) designed to run at 900 RPM at 60 Hz.Preferred Dimensions: The first propeller has a diameter of 16-20 inches.