The SCUD data product is an estimate of upper-ocean velocities computed from a diagnostic model (Surface CUrrents from a Diagnostic model). This model makes daily estimates of ocean currents by combining geostrophic and Ekman currents. The estimate is computed through derived coefficients such that the results best match ocean drifting buoys. The currents therefore are a best-estimate of currents at 15 meters (drifting buoys are drogued at 15 meters). The dataset is intended to diagnose trajectories of a tracer floating near the surface such as marine debris, oil spills, etc. The data are provided on a 1/4-degree grid for the Pacific.