Abstract
One of the crucial systems of sea mining ship for poly-metallic concretions is its motion control system (SMC). Power of such system depends on sea environment characteristics and main dimensions of the ship. It can be expected that it will have important influence on total power of the ship's power plant and in effect on the mining ship's dimensions. In this paper is presented one of the possible ways of preliminary estimation of design power of SMC system for sea mining ship. Since details of design solution of such system for the ship in question are unknown (ships of the kind have not been built so far) the presented results should be considered to be the first estimation of the order of the power demand.