Large ships and offshore structures face a serious risk of damage from severe wave events in rough waters. Slamming events occur when the hull of a ship slams the water surface, or a wave slams a ship, potentially causing catastrophic damage. Simulations of slamming are complicated because large structures are flexible, and the slamming loads depend on the structural deformations. Computations of hydroelastic slamming require a structural code to evaluate stresses in the structure and assess the risk of the structural damage, a hydrodynamic code to determine the slamming loads, and a coupling interface between these codes. The weakest element in this scheme of the risk assessment, which is used by certification companies on a daily basis, is an interface code. It is shown below that in slamming simulations, where the added-mass effects play the leading role, construction of such an interface is not straightforward. To be confident in the results of computer simulations of hydroelastic slamming, the computed results should be very carefully validated. This validation can be done, in particular, by using analytical, fully coupled models of slamming. As a result, the risk assessment becomes more reliable leading to safer ship operations at sea.