Abstract: A thermodynamic flotation engine designed to operate using waste heat contained in hot fluids such as water is provided which is of simple construction and allows for continuous operation with no other outside energy source being required. The engine includes an upright fluid tank adapted to receive the hot fluid, with a continuous loop member having a series of discrete bladders mounted thereon. The loop member is supported for continuous movement of successive portions thereof into and out of the fluid filled tank from bottom to top, as by means of a pair of spaced apart pulley members.