Hydro-jet propulsion device for driving and controlling of particularly flat-bottomed watercrafts

A hydro-jet propulsion device for driving and controlling shallow draught watercraft, comprising:

• hull means;
• means defining a downwardly opening recess in a bottom surface of said hull means, said opening having a central vertical axis and an inner surface contour over the entire axial extent thereof which is concentric with said central vertical axis;
• elbow means and support means for rotatably supporting said elbow means in said downwardly opening recess and for movement about an axis of rotation which is coaxial with said central vertical axis, said elbow means having a bottom surface which is generally flush with the outer surface of said hull means, said elbow means additionally having a radially outer surface contour conforming to the contour of said inner surface of said downwardly opening recess and being spaced slightly radially inwardly therefrom, said elbow means having means defining a passageway therethrough, said passageway having first and second segments, each of said segments having a longitudinal axis inclined to said axis of rotation of said elbow means, each of said first and second segments opening outwardly of said bottom surface of said elbow means and at locations whereat the central axes of the two openings in said bottom surface of said elbow means are spaced radially outwardly from said axis of rotation of said elbow means;
• and
• propeller pump means and drive means therefor, said propeller pump means being mounted in said first segment of said passageway for drawing in water through one of said two openings in said bottom surface and ejecting water from the other of said two openings in said bottom surface, the axis of rotation of said propeller pump means being inclined to said axis of rotation of said elbow means, said drive means including means facilitating a drive of said propeller pump means about said inclined axis of rotation thereof.