Main theme of the Symposium is Diversity, providing a forum dealing with use of hydrographic expertise for both traditional and non-traditional survey applications. Topics include Visualisation via Video Gaming, Remote Sensing Imagery, Multibeam Sounding, Electronic Charting, Coastal Zone Surveying, Marine Archaeology, Arctic Bathymetry, Environmental Mapping & Monitoring; also prominently featured will be presentations by representatives of the Geological Survey of Ireland and the Marine Institute of Ireland on the Irish National Seabed Survey project, currently the world's largest hydrographic venture involving offshore mapping of an area ten times larger than Ireland itself.

Proceedings are also being supported by a series of workshops and demonstrations as well as an exhibition of equipment and services by nearly 30 organisations. Participants to date include Applanix, Atlas Hydrographic, CARIS, CodaOctopus, Gardline, GeoAcoustics, Geological Survey Ireland, Geomatrix Earth Science, Innomar Technologie, IVS-NetSurvey, Ixsea, Kongsberg Maritime, L-3 Communications ELAC Nautik, Marine Institute (Galway), Marintech, Nautronix, Odom Hydrographic Systems, Ohmex, Ormston Technology, QPS, Reson, Ruco, SevenCs, Sonardyne, Systems Engineering & Assessment, Tenix Defence Systems, Valeport and VT TSS.

Details on Hydro4, which is expected to attract a wide international audience of more than 350 delegates, are available from: Hydro4, 74 Callington Road, Saltash, Cornwall PL12 6DY, UK (Tel: +44 (0)1752 843461 Fax: +44 (0)1752 848267 Email: hydro4@ hydrographic society. org Web: www.hydrographicsociety. org/hydro4).