Abstract: A propulsion system 2 for a waterborne vessel 4 comprises a hull structure 6, typically for a full or semi planing boat. The propulsion system 2 comprises a pod housing 8 having a front end 10 and a rear end 12, a propeller 14 and a propeller shaft 16. The propeller 14 is disposed externally at the front end 10 of the pod 8 and is rotatable about a longitudinal axis 18 of the propeller shaft 16, the propeller shaft 16 being drivingly connected to drive means. The drive means comprises a transmission unit 20 and a power unit 22 in the form of a diesel engine. In FIG. 1 the diesel engine is shown disconnected from the transmission unit 20. The power unit 22 is disposed within the structure of the hull 6 and, in this particular embodiment; the transmission unit 20 is disposed substantially outside the structure of the hull 6. The hull 6 is formed with a port 24 through which an interface unit 26 extends. The interface unit 26 provides means to transmit the torque of the power unit 22 to the transmission unit 20.