The authors computed pressure distributions on a flat plate when it oscillates on water surface in the former report. It is generally believed that their results stand for of a very shallow draft ship, but there lies some question if it does really. For this question, the authors develope the discussion and especially with regard to the end shape. Then, if the draft of a ship is very deeper than the wave height, the flat plate modeling is adequate, and the solutions obtained correspond to a ship having flared side wall but there is a difficulty for such ship that the wetted surface area changes periodically when she dipps and heaves. The second part of the present report is devoted to the discussion about the resolvent of the integral equation of the boundary value problem. Applying this result, the authors discuss problems, the effect of small slits, the slight change of the breadth and the wave-excited swaying force of a flat plate.