A B S T R A C TWe review here the results obtained during the past several years in a series of computational and experimental investigations aimed at understanding the origin of high-force production in the flapping wings of insects and the flapping and deforming fins of fish and the incorporation of that information into bioinspired vehicle designs. We summarize the results obtained on pectoral fin force production, flapping and deforming fin design, and the emulation of fish pectoral fin swimming in unmanned vehicles. In particular, we discuss the main results from the computational investigations of pectoral fin force production for a particular coral reef fish, the bird wrasse (Gomphosus varius), whose impressive underwater flight and hovering performance matches our vehicle mission requirements. We describe the tradeoffs made between performance and produceability during the bio-inspired design of an actively controlled curvature pectoral fin and the incorporation of it into two underwater flight vehicles: a two-fin swimming version and four-fin swimming version. We describe the unique computational approach taken throughout the fin and vehicle design process for relating fin deformation time-histories to specified desired vehicle dynamic behaviors. We describe the development of the vehicle controller, including hardware implementation, using actuation of the multiple deforming flapping fins as the only means of propulsion and control. Finally, we review the comparisons made to date between four-fin vehicle experimental trajectory measurements and controller simulation predictions and discuss the incorporation of those comparisons into the controller design.