With the progress of the ocean development, the estimation of the hydrodynamic forces acting on floating and/or submerged bodies in shallow water, has come into an important and urgent problem for the prediction of the motion of the structure and, in addition to model tests, some theoretical approaches have been made by several authors using the eigenfunction, expansion or the singularity distribution methods. Moreover, the introduction of the finite element method to flow problems has made possible to analyse the flow field around the complicated body configuration and the bottom topography with ease. In the present paper, firstly the author analysed various kinds of the two-dimensional problems in shallow water by means of the finite element technique called the method of superposition proposed by Yamamoto and the author in the first report, taking advantage of the linearity of the governing equations and the asymptotic behaviors of the solution at infinity. The results showed good agreement with previous authors'. Secondly, the author formulated a new solution method based on the extended three-dimensional Haskind's relation between the radiation and the diffraction potentials corresponding to Bessho's theory, and conducted a few numerical calculations for an axi-symmetric body.