Radar Cross Section (RCS) from sea surface carries rich informations about sea states. Many works have been developed to compute RCS from this surface. The Classical Moment Method became an effective tool since it works for a very large class of surface shapes and scattering mechanisms. However, it requires a small mesh step ( =10) which produces a high number of unknowns. Besides, for a highly curved surface like the sea, we need a much smaller mesh step to avoid the factitious geometric discontinuities between the patches. In this work, we propose to use the Higher-Order Moment Method (HO-MoM) with NURBS patch to increase the mesh step into . We show that this method can solves the scattering problem with fewer number of unknowns.