The arrangement includes at least one steering electric motor rotating the propulsion unit via a force transmission arrangement. The force transmission arrangement includes a differential including a first shaft connected to the steering electric motor, a second shaft connected to the propulsion unit, and a third shaft connected to a brake device. The third shaft is locked from rotation when a torque produced by an external force on the propulsion unit is below a threshold value, whereby power is distributed only from the steering electric motor to the propulsion unit or vice a versa. The third shaft is allowed to start rotating when the torque produced by the external force on the propulsion unit exceeds the threshold value, whereby power is distributed from the steering electric motor to the rotation of the propulsion unit and to the brake device or from the rotation of the propulsion unit to the steering electric motor and to the brake device.