Abstract: A dynamically balanced, fluid submersible, self propelled object that may be suitable as a toy or for transporting man and material. The object, through a combination of negative and positive buoyancy, and control surfaces, can descend and ascend repeatedly. The submersible object includes a tail fin assembly of essentially four fins radially extending from the object body, and a pair of wings, where the position and size of the fins and wings are controlled and balanced by specific perimeters to ensure the self propulsion.