The Probability of Close Overtaking in Fog

Abstract

In areas of high marine traffic density it has been necessary for IMCO to introduce traffic separation schemes to reduce the total number of encounters, and in particular the dangerous head-on encounters. It is now widely acknowledged that separation schemes can and do improve safety. However, as a side effect they unfortunately increase the number of overtaking encounters. For example the introduction of a separation scheme in the Dover Strait (with 1 per cent of ‘through rogues’) has increased threefold the proportion of potential overtaking encounters.