Numerical simulation of 3D complex waves impacting on ships and other floating objects are carried out using unstructured finite element meshes with more than one billion tetrahedral elements. Here, the governing equations are the Navier-Stokes equations written for two incompressible fluids. An interface function with two distinct values is used to locate the position of the free-surface. The stabilized finite element formulations are written and integrated in an arbitrary Lagrangian-Eulerian domain. This allows us to handle the motion of the time dependant geometries, such as the floating objects with moving the computational nodes. In the mesh-moving scheme, we assume that the computational domain is made of elastic material. The linear elasticity equations are solved to obtain the displacements for each computational node. The nonlinear rigid body dynamics equations are coupled with the governing equations of fluid and are solved simultaneously to update the position of the floating objects.