The wave-making characteristics of after hull bodies are more or less affected by the viscosity of water, to which the most important cause of the discordance between the theory and the experiment may be attributed. The authors attempt to find by the photographic method to what extent the mentioned effect of viscosity might be changed according to Froude number as well as to the fineness of the run. The results are that the observed position of the stern wave separation varies with Froude number and the fineness quite in a similar manner with the shifting factor δ, which has been obtained from the comparison between the measured and the calculated wave-making resistance.