Correct assessment of entry of a solid through a free surface is important in various hydrodynamic applications. It is especially crucial when dealing with ship motion behavior in high sea states where slamming impacts are likely to occur. There is a wide range of numerical methods designed to compute forces and pressures on the hull triggered by this phenomenon. However, from an industrial perspective, it is important to discriminate between them and find a compromise between CPU time, set-up time (i.e. engineering time) and accuracy. In this paper, we aim at comparing the merits of three different classes of methods: potential theory based on a Wagner model, CFD based on finite volume method with a VOF interface and the lagrangian SPH method. The numerical results are compared against experimental data from WILS campaign.