A boat hull with a marine drive assembly being mounted in an opening in said boat hull, said marine drive assembly comprising: a drive unit extending downwardly through the opening in the boat hull, said drive unit having an upper unit adapted for trim actuation, and a lower unit coupled to said upper unit; an enclosure assembly disposed within the hull of the boat and sealed such that water is substantially prevented from entering the boat hull through the opening in the boat hull that receives the drive unit and which is adapted to enhance hydrodynamic efficiency and wake performance of said drive assembly; and a trimming actuator assembly for adjusting trim of said upper unit, said trim mechanism including a trim shaft for trimming said upper unit about a trim axis, a rotary actuator for applying rotational movement to said shaft, and a selectively energized member for actuating said rotary actuator; characterized in that said enclosure assembly includes an upper portion disposed substantially within the hull of the boat, a gasket flange plate secured to said upper portion with a substantially water-tight seal, said gasket flange plate having a gasket flange extending radially outward, a retention plate for clamping said gasket flange plate against the hull forming a substantially water-tight seal, an O-ring gasket member formed from a resilient material for sealing a junction between said gasket flange and the hull and for further sealing a junction between said retention plate and said gasket flange, wherein said retention plate and said gasket flange plate are configured to closely follow a contour of the hull thereby providing a substantially seamless interface to the boat hull; a drive mechanism adapted to provide drive forces to a propeller, said drive mechanism adapted such that said propeller, said drive unit and a marinized motor are positioned on a substantially common central line along a direction of thrust. a drive unit extending downwardly through the opening in the boat hull, said drive unit having an upper unit adapted for trim actuation, and a lower unit coupled to said upper unit; an enclosure assembly disposed within the hull of the boat and sealed such that water is substantially prevented from entering the boat hull through the opening in the boat hull that receives the drive unit and which is adapted to enhance hydrodynamic efficiency and wake performance of said drive assembly; and a trimming actuator assembly for adjusting trim of said upper unit, said trim mechanism including a trim shaft for trimming said upper unit about a trim axis, a rotary actuator for applying rotational movement to said shaft, and a selectively energized member for actuating said rotary actuator; characterized in that said enclosure assembly includes an upper portion disposed substantially within the hull of the boat, a gasket flange plate secured to said upper portion with a substantially water-tight seal, said gasket flange plate having a gasket flange extending radially outward, a retention plate for clamping said gasket flange plate against the hull forming a substantially water-tight seal, an O-ring gasket member formed from a resilient material for sealing a junction between said gasket flange and the hull and for further sealing a junction between said retention plate and said gasket flange, wherein said retention plate and said gasket flange plate are configured to closely follow a contour of the hull thereby providing a substantially seamless interface to the boat hull; a drive mechanism adapted to provide drive forces to a propeller, said drive mechanism adapted such that said propeller, said drive unit and a marinized motor are positioned on a substantially common central line along a direction of thrust.