Methods and apparatus to adjust hydrodynamic designs of a hydrokinetic turbine are disclosed herein. An example turbine to be placed in a body of water includes a generator having a frame, an inlet, a first set of vanes disposed in the inlet, a second set of vanes, and a shroud. The inlet, the first set of vanes, the second set of vanes, and the shroud are removably coupled to the frame. The first set of vanes in removably coupled to the inlet.