In the following paper, which was presented to a meeting of the Institute held in London on 30 March 1966 Captain Wepster describes the results of an investigation undertaken by the Holland-America Line into collisions on the main navigable rivers and inland waterways of north-west Europe, including the United Kingdom. On the basis of a previously published paper by Beattie, it was estimated that the main rivers worth investigating were the Schelde, the Thames, the Elbe, the New Waterway and the Weser. A speed analysis and plot of casualties of these rivers is presented.