Abstract: A water-jet is mounted rigidly entirely outboard of the boat and driven from an inboard engine by an interconnecting chaft through the transom. The tail nozzle is mounted concentric of and spaced from the pump chamber of the jet and extends rearwardly therefrom axially thereof. A butterfly trim vane is pivotally mounted on a transverse horizontal axis in the tail nozzle and is adapted to close the nozzle for blocking the jet and compelling a reverse flow of the water from the pump through passages between the pump chamber and tail nozzle. A steering vane is mounted on a vertical axis rearwardly of the tail nozzle and carries a rudder disposed beneath the jet steering vane for steering during reversal of the jet. The engine exhaust is introduced to the jet stream within the tail nozzle and has a by-pass operable during reverse of the jet stream.