A new type of miniature swimming vehicle is discussed in this study. Propulsion is developed through a posteriorly mounted fin that laterally oscillates in a fish-like manner. The fin is driven by a kinematic mechanism, which is in turn actuated by two high-deflection, curved-beam piezoelectric actuators. Analytical theories relating to individual components of this multidisciplinary system are covered, including discussions of kinematics and fin propulsion. A summary of the generation of static and dynamic actuator models is presented. The physical evolution of an actual swimming vehicle is discussed through the positive and negative aspects of several design iterations. The current vehicle status is presented in detail in terms of its physical design, operation, and controls and is evaluated in terms of speed and maneuverability.