Captain F. J. Wylie is, of course, the complete master of the cumulative turn in all its aspects, not for a moment omitting the mathematical. And Commandant L. Oudet has greatly contributed to the study of this important and interesting subject in collision theory. He has provided detailed and lucid information on actual cases, brilliantly researched and reconstructed in a manner that would do credit even to the immortal analyst the Chevalier C. Auguste Dupin. There is indeed little that can be added to what these two and other distinguished authors have already recorded in the pages of this Journal, most notably in Wylie's 1963 article, Collision at Sea in Fog: The Commonsense Approach (16, 100), Oudet's 1965 article, Collision and the Courts (18, 188), and Wylie's article, Legal Aspects of Radar and Collision (18, 203). It also turns out that Wing Commander E. W. Anderson has made a most important contribution to this subject.