The traditional numerical method for the evaluation of the effect of hydrodynamic loads over offshore structures consists, in general, of two steps: first these loads are obtained assuming that the structure is a rigid body; then, equivalent static loads are applied to the elastic body model. From this procedure good results can be deduced for a variety of offshore structures, but it’s inadequate for large constructions like, for example, the modern container ships or even some FPSO (Floating Production Storage and Offloading) platforms. The former, due to the open cross section and length beyond 300m, has low structural stiffness. This characteristic facilitates the excitation of the natural modes of vibration of the structure by wave loads. Consequently, a coupled analysis of the structural and hydrodynamical phenomena must be applied. This work uses a methodology on hydroelasticity that considers this coupling on the vertical bending of a container ship. The methodology employs the finite element method for a one-dimensional beam model as a representative of the structure, and the tridimensional panel method as a representative of the hydrodynamic model. The obtained numerical results are validated through comparison with results published in another study.