This paper describes the procedure for designing ship propellers. The parameters used to design the screws are listed and described. General classification of ship propulsors and their most important characteristics, kinematic properties, propeller geometry are given. The effects of cavitation on the ship's propeller and its effect on the propellers usability. In the experimental part of the paper, a srcew design test was performed using the Wegeningen basin series diagram, the geometry od ELICHE RADICE B6 for Majka Marija fishing vessel was tested using Prop Scan technology and differences in measured values and those given by the factory screw design where observed. On the ship Naše more a special program was made for the correction of the ship's bolt and the improvement of the ship's specifications after the operation of the correction of the bolt and comparasion with the old parameters. The project is shown for a bulk carrier screw built in a Split shipyard. The most optimal screw was selected in the calculation, the marine engine was tested, future performance of ship was examined , the risk of cavitation and conclusion were reached on the basis of the examination.