Abstract: Method and arrangement for the reduction of the resistance to rotation of the propeller (3) of a ship (1) going in ice when the ice increases the resistance to rotation of the propeller to a level higher than when sailing in open water. When the resistance to rotation increases, gas is passed to the propeller (3), and the supply of gas is adjusted when the resistance to rotation is changed. The supply of gas may be continual, but as a rule it is used only for short periods in order to correct the speed of rotation of the propeller to the appropriate level.