This chapter proposes a viable coupling strategy employing a combination of two-phase flow Computational Fluid Dynamics model with a fully dynamic multibody and mooring dynamics model, suitable for high-fidelity simulation of floating moored structures. It describes the complete development process, implementation, and testing of a high-fidelity numerical framework for Fluid Structure Interaction of moored floating structures. The toolkit solves the Navier-Stokes equations for two-phase incompressible, immiscible flow. The computational cost associated with this approach is nevertheless higher than using a single transport equation for Volume Of Fluid or level set method. Waves are introduced in the domain at the generating boundaries and any reflection or transmission of the waves are absorbed using the relaxation zone method. A triangular (in 2D) or tetrahedral (in 3D) mesh was used to discretise the flow variables in space.