Most wave-structure interaction models are based on a numerical solution of boundary value problems for partial differential equations. Difficulties experienced by numerical wave tank users are very similar to difficulties of wave generation in experimental wave facilities. Effective absorption of reflected waves normally requires large absorbing zones and thus larger computational domains. The idea of hybrid models has received considerable attention recently and numerous hybrid models have been developed. The most popular couple for creating a hybrid model are a boundary element model as a computationally efficient component and volume of fluid as an advanced component. Fully nonlinear potential flow theory models differ by particular methods of solving Laplace equation for velocity potential in the fluid domain and by methods of specifying a fully nonlinear boundary condition on a moving free surface. A more flexible formulation was therefore developed with Green’s theorem applied in physical space.