The comparative analysis of different control ways is executed by the electric drive of a dry dock dewatering pumps on the criterion of a minimum of consumable energy, when permanent rotation frequency of driving wheel, serve, OIR is supported or the optimal control law will be realized. Research is conducted for three types of pumps with an asynchronous drive - horizontal centrifugal, submersible mixed - flow and vertical axial with the hardly envisaged blades. It is set as a result of analysis, that by transient time tightening as a result of smooth rotation frequency change of pump driving wheel, it is possible substantially to promote a duty cycle output-input ratio in comparing to the base operating condition. At the same values of spades of rotation frequency, torque, power the least economy and most productivity are characterize base operating condition with permanent rotation frequency. A middle economy and productivity are characterize the mode of equal serve other things being equal. And a most economy and the least productivity are characterize the mode of equal values OIR. Optimal mode, occupying frequencies of rotation at the same lances, power intermediate position between the mode of equal serve and OIR, some yields to on an economy the last, but at the same time characterized and considerably by the less degree of process tightening.