In 2005 the CoastGIS symposium and exhibition was once again held in Aberdeen, Scotland, in the UK, the second time that we have had the privilege host this international event in the city of Aberdeen. This was the 6th International S- posium Computer Mapping and GIS for Coastal Zone Management, a collabo- tion between the International Cartographic Association’s (ICA) Commission on Marine Cartography, and the International Geographical Union’s (IGU) Comm- sion on Coastal Systems. The theme for 2005 was: De ning and Building a Marine and Coastal Spatial Data Infrastructure. As a major coastal event, the CoastGIS series of conferences always attracts an international audience of coastal researchers, managers, and pr- titioners who use one or more of the geospatial technologies (e. g. GIS, GPS, digital mapping, remote sensing, databases, and the Internet) in their work. The CoastGIS series is fundamentally an international event which over the years has gained a strong following attracting delegates from around the globe. Hosted by the University of Aberdeen – at the Aberdeen Exhibition and Conference Centre (AECC) – once again CoastGIS 2005 provided an opportunity to communicate the results of a wide range of innovative scienti c research into coastal and marine applications of the geospatial technologies, including remote sensing, Geograp- cal Information Systems (GIS), Global Positioning Systems (GPS), databases, data models, the Internet and online mapping systems.