Reduced manning levels, the lack of skilled maritime labour and new satellite navigation systems have created a need for electronic charts in merchant ships. Developments in information technology have made it possible to design and produce these charts and the equipment to display them. It is essential that shipowners and others understand the issues which affect the use of these charts and equipment. It is also important for users to understand the effects that the revolution in satellite technology is having on all types of charts, paper and electronic. Only with this knowledge can shipowners appreciate the economic and operational benefits of using electronic charts, and IMO complete its work on the safety rules for the carriage and operation of all types of electronic charts and equipment for merchant ships.

This paper examines a Synthetic Aperture Radar (SAR) image of the Thames Estuary aided by the relevant nautical chart, tidal, weather and shipping information of the area. By correlating this information it is possible to identify gross sediment transport which would otherwise be hard and financially expensive to detect. Seabed topography, seabed pipelines, some shipping, coastal zone features and different water parcels can be identified.

In this paper, the methods of collision avoidance by radar which have been used in the radar simulator course at Chinese marine colleges are introduced. Then some other methods of estimating the risk of collision, safe passing distance and course alteration in radar collision avoidance are presented.