A marine vessel propulsion assembly has an elastically suspended gearbox with an output drive shaft guided in an axial bearing with a rigidly suspended bearing housing. Free space is provided in the axial bearing for allowing movement of the output drive shaft in the radial direction, wherein the output drive shaft is freely movable radially within the free space. A supporting ring with sliding elements for axial guidance of the output drive shaft is arranged in the axial bearing. The supporting ring is hydraulically supported by a large number of pistons so that the supporting ring can match itself to angular displacements of the output drive shaft and can always completely and uniformly support the sliding elements on the bearing circumference.