Electrically-powered model boats exclusively use Direct Current (DC) motors, although there are thousands of different types and sizes. Essentially they all involve using the power supply to energise a coil or coils of wire inside the motor. These coils form the armature of the motor. The electrical energy creates a magnetic field in the coils which in turn rotates the armature inside the motor. The armature shaft extends beyond the end bearings in the motor case and the propeller shaft is connected to it via a coupling. There are very many websites which show their construction and operation, with both coloured diagrams and animated graphics.