Modeling of radar signature of sea targets in dynamic sea states is a critically important problem in developing methods of detection and identification of potentially threatening ships. As most maritime radars operate at X-band, this electromagnetic (EM) problem has an extremely large electric-size and it is further complicated by the sea wave phenomena. Simulation tools exist for high-frequency EM simulation. However, existing tools are incapable of modeling the fine features on the topside of ships that often have significant scattering contributions due to their comparable size to X-band wavelength. They are also incapable of capturing the interaction between ships and complex sea states and are not suitable for state-of-the-art Graphic Processing Unit (GPU) or GPU-cluster acceleration. To address this, IAI and its collaborators from Auburn University have been awarded a new contract entitled, “RARSP: Rapid and Accurate Radar Signature Prediction.” A hybrid method will be developed based on the novel Bidirectional Analytic Ray Tracing (BART) algorithm and the 3D fast Method of Moments (MoM) algorithm. In addition to the fine features of ships, the proposed tool can also take into account the scattering of rough sea surfaces. Both BART and MoM can be accelerated by inexpensive GPUs. This technology will provide significant benefits to a variety of commercial and military radar sensing applications of mixed-scale targets, including aviation, boats and ships, spacecraft, ground vehicles, and fixed installations.