Ship-motions with forward speed in infinite depth

We propose in this paper two 3D methods to solve the diffraction-radiation problem with forward speed. This physically complex problem is reduced to the determination of the potential of the flow around the immersed part of the body. Boundary conditions are linearized and calculated at the mean bou ndary position. The total velocity potential is obtained by summing incident, diffraction and radiation velocity potentials. Each problem is resolved by two 3D singularities methods (mixed distribution and sources distribution). The Green function is determined with the almost perfect fluid assumption, or with the perfect fluid assumption and a radiation condition at infinity.