Abstract: A propulsion module, a propulsion system, a watercraft, an assembly method for a propulsion module, an assembly method for a propulsion system and an assembly method for a watercraft are provided. The propulsion module includes a waterjet. The propulsion module also includes an electric motor configured to channel seawater through the waterjet, wherein in use, the electric motor is configured to be externally passively cooled by surrounding seawater. Further, the propulsion module includes an electronic speed controller (ESC) connected to the electric motor and configured to control the electric motor, wherein in use, the ESC is configured to be externally passively cooled by the surrounding seawater.