Abstract: A central axis water turbine is described which comprises a turbine body having a central axis; a rotor mounted on the turbine body for rotation about the central axis, the rotor comprising a central hub supporting a plurality of blades, each blade extending from a blade root mounted on the hub to a blade tip; a generator driven by the rotor; and a housing surrounding the rotor and adapted to direct water flow towards the rotor, the housing converging from a front opening forward of the rotor to a narrower throat adjacent the turbine body; wherein the blades are splayed rearward from the blade root to the blade tip by a tilt angle of 1° to 20° from a plane perpendicular to the central axis.