NOVELTY - A turbine (100) has two blades (105) that rotate in a single direction when exposed to fluid flow. The blades are joined to a central shaft (110) by lightweight radial spokes (115a-c) so that the rotating blades cause the shaft to rotate. The blades have a uniform airfoil-shaped cross section that presents a non-zero angle of attack to the current. The blades wind in a spiral trajectory and rotate around the shaft. The blades have a variable radius along the shaft's length such that the measured distance from the blades to center shaft is greater near the turbine's center than at either end.    USE - Unidirectional turbine for harnessing energy from a wide range of sites and water flow conditions. Uses include but are not limited to tidal currents, open ocean currents, rivers, causeways, canals, dams and any other natural or manmade water flow.    ADVANTAGE - The unique design provides for a highly efficient, easily produced, scalable turbine that produces high power output at low fluid velocity and efficiently harnesses energy from a wide range of sites and water flow conditions. The method of making the turbine is a low cost, easily reproduced and scalable process since the blades and radial spokes can be formed through any number of known manufacturing methods e.g. machining, extrusion or injection molding. The joining of the blades to the central shaft with several lightweight radial spokes eliminates a need for traditional heavy spokes and/or end disks that decrease efficiency and generate end-turbine losses. The unique trajectory of the blades (spiral wound and barrel bowed) increases blade strength and reduces stresses and stains under load conditions. The non-zero angle of attack maximizes torque generated by the turbine and maximizes turbine efficiency in a range of 30 to 50 percent and more preferably at about 43 percent. The torque generated peaks between approximately 50 and 200 turbine revolutions per minute (rpm) in response to fluid flow velocities ranging between approximately 1.4 to 4.0 meters per second (mps). The torque generated at a flow of approximately 3 mps produces optimal torque peaking in a range of about 800 to 1200 Newton-meter (N-m) at rpm in a range of about 50 to 190 rpm, and more preferably produces torque of about 1000 N-m at about 140 turbine rpm.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for generating power.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the turbine.    Turbine (100)    Blade (105)    Central shaft (110)    Radial spokes (115a-c)    Two dimensional mirror image projection of turbine (120)