Since 1944, when one of the present Authors (INUI) and his collaborator calculated mathematically the wave-making resistance of ships in a shallow sea, necessity has long been recognized for making further quantitative investigations regarding to the practical adaptability of the theory. The following notes are aimed for clarifying the still remained question to what extent such a linearized wave-making theory can be safely applied in cases of a restricted water ( b = h =finite) as well as a shallow water ( h =finite, b =infinitive), where h denotes the depth of a water, b the width. A 1.750 m mathematical model S-201, whose equivalent source distribution is known, is towed in the Tokyo University Tank at the depth of water h/L =1.371, 0.400, 0.300 and 0.200. Comparatively good coincidence has been obtained between the calculated and measured wavemaking resistance, excluding the narrow critical range of F_h =0.820.95 where the KREITNER'S non-linear restricted water effect is clearly observed especially at the shoalest depth h/L =0.200.