[Reprinted from the PRocEEDINGS oF THE Royat Soctery, A, Vol. 108.] 
Wave Resistance: the Effect of Varying Draught. 
By T. H. Havetocr, F.R.S. 
(Received June 5, 1925.) 
1. In previous studies in the theory of wave resistance, while the water- 
plane section of the model was of a reasonably ship-like form, the draught 
was assumed to be infinite. In the following paper the model has the same 
simple lines and has vertical sides, but the draught is finite. The investi- 
gation shows how the resistance at different speeds depends on the draught, 
but‘it was undertaken specially for other reasons. In view of certain applica- 
tions, it was important to find how the interference effects due to bow and 
stern waves are affected by varying draught. It is shown now that these 
become less prominent with diminishing draught, but the maxima and minima 
occur at practically the same positions. Further, when the ratio of draught 
to length is of the order of the values in actual ship models, one is in a position 
to attempt a comparison between the absolute values of theoretical and 
experimental results, 
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