Modern high-fidelity aerospace analysis and design tools require watertight, analytically- smooth representations of the configuration under consideration. Most recently created geometric models have appropriate representations; unfortunately, legacy configurations often do not have a geometric representation commensurate with the analysis task at- hand. Either the analytic data has been lost and the remaining configuration is in a discrete setting, or the legacy analytic information is not smooth or is not closed at the required precision. In order to utilize high-fidelity analyses on these legacy configurations, it is necessary to have a tool through which a user can easily create the required smooth watertight geometric model. Described here is a new interactive system, named SLUGS (Static Legacy Unstructured Geometry System), which starts with a cloud of points (which may be fully- or partially- connected through a surface tessellation) and which “fits”: the cloud to a watertight set of B-spline surface patches driven by the user. The process for this conversion, as well as the key technologies that are used, are described in this paper.