A non-volatile memory device and a program method thereof are disclosed. The field shaper assembly is then rotated within the field shaper fixture such that the field shaper assembly is oriented on a horizontal axis. The system continuously monitors the position and heading of the boat and compares it with the stored coordinates of the selected anchoring location to generate control signals for the steerable motor. The threadform uses a combination of thread cuts that vary in shape, pitch, andor thread cone angle to provide load and stab flanks, as well as a load path, that vary from one axial end of the engaged thread to the other.