Nautical variable steering and propulsion assembly

A nautical variable-trim steering and propulsion assembly (10) that can be associated to the underside of the bottom (11) of a watercraft and in communication with a motor unit (12) located within said watercraft, said assembly (10) comprising a widened base (13) for resting on said watercraft, a shaft element (14) connected on one side to said base (13) and on another side to a supporting torpedo-shaped element (15) defining the axis of rotation (16) of at least one propeller (17) set at at least one end of said torpedo-shaped element (15), moreover being provided a directional fin-shaped skeg (18, 18′) associated to said torpedo-shaped element (15), rotating about the axis of said shaft element (14) for controlling the directionality of said watercraft, characterised in that said directional fin-shaped skeg (18,18′) is in addition rotating about an axis parallel to said axis (16) of said at least one propeller (17) defined by said torpedo-shaped element (15), being provided releasable constraining means for constraining at least temporarily said directional fin-shaped skeg (18, 18′) in an inclined position with respect to said torpedo-shaped element (15).