The project entails the design and wind tunnel testing of surfboard fins through the application of aerospace industry practices. To obtain the most efficient fin with qualities desirable to the surfer, aerodynamic efficiency must be maximized to obtain directional stability, maximize velocity, and avoid stalling. In Phase I of the project, five fins were manufactured and tested in the Micaplex Low-Speed Wind Tunnel, in which the saltwater conditions wherein surfboard fins operate were mimicked using the principle of dynamic similarity. The Winglet Fin was selected for further analysis in Phase II, in which surface oil flow visualization was utilized to inspect the surface flow over a range of angles of attack (α) to understand how fin geometry affects hydrodynamic performance. The modern winglet is a common performance-enhancing device developed to overcome aerodynamic losses due to wingtip vortices. This motivated winglet implementation on the surfboard fin, which possesses similar characteristics to an aircraft wing. Force measurements were collected for a 2:1 scale surfboard fin model to verify estimated forces and stall angle. Surface flow patterns were qualitatively observed via oil streaklines. From the data, instantaneous surface flow qualities were observed over the α range. The locations of open and closed separation points were detected, as well as three-dimensional flow effects and pre- and post-stall vortex behavior. Flow characteristics were analyzed to identify regions of turbulence and high surface shear stress. By applying technology normally reserved for aerospace applications, this project hopes to bring a more innovative culture to the surfing industry.