Between April and about September 1977 almost all the present buoys in the southern North Sea, Dover Strait and eastern part of the English Channel will be changed and a completely new system introduced in an area much used by international shipping of all types. Why has this come about and how can the new system be recognized on charts and in the water? What are the most significant changes and where will the system be applicable? The answers to these questions are given in the Hydrographic Department's new publication NP 735, IALA Maritime Buoyage System A, Edition 1, 1976, which is now available from Admiralty chart agents. It should be studied carefully by all who go to sea or are concerned with marine operations in north-west European waters.