In this paper which was presented at an Institute meeting in London on 17 November 1971, Mr. O'Hagan describes a system for advising cooperating ships in a Surveillance Area. The system includes accurate position sensing through on-board equipment, high frequency telephonic communication, a general survey of all shipping and other hazards in the area based on primary radar, analysis of the data by computer, and the employment of an experienced Master Mariner ashore to assess the situation and offer advice to the cooperating vessels.

The discussion was opened by R. H. Farrands, Vice-President of the European Maritime Pilots' Association. The Chair was taken by the President of the Institute, Rear-Admiral G. S. Ritchie, C.B., D.S.C.