The invention comprises a scalable, configurable “propulsor” system. A propulsor system is an assembly of individual propulsors that act in concert to form a substantially continuous control surface that undulates in a working fluid. Each propulsor is driven and configured by computer-controlled actuators so that the control surface undulates in various wave forms. Optional actuators that may refine the surface shape include an “orientation” actuator that drives rotation about the propulsor's longitudinal axis, and a “geometry” actuator that controls each propulsor's geometric configuration.