Many simplified models for practical analysis of water impact are based on the Wagner
theory (Wagner, 1931). The Wagner approach assumes a potential flow. Moreover, the
boundary conditions are linearized and imposed on the initial (flat) liquid free surface. Several
improvements of the original Wagner theory have been proposed over the years. Cointe and
Armand (1987), Watanabe (1986) and Zhao and Faltinsen (1993) used the method of matched
asymptotic expansions to account for the effect of the jet flow on the distribution of
hydrodynamic pressure at the intersection between the liquid free surface and the body. In
order to extend the range of validity of the Wagner theory to large deadrise angles, Zhao et al.
(1996) proposed the generalized Wagner approach, in which the real shape of the solid and
the exact kinematic boundary condition are employed for the computation of the fluid flow,
see also (Mei et al., 1999; Faltinsen, 2002; Malleron and Scolan, 2008). Other theoretical
models for the prediction of slamming loads were proposed by Vorus (1996), Korobkin
(2004) and Oliver (2007).