This paper describes the “CIAO” project, based on an international initiative, part of the « Programme Régional de Conservation de la Zone Côtière et Marine d'Afrique de l'Ouest » or PRCM (Regional Program for the Conservation of the Coastal and Marine Area of West Africa). It leads to a web portal of information for the West African coastal zone. Investigations among the main producers of information have led to a first inventory of available geographical information. The information has been described in metadata files (ISO 19115) which have been collected into a catalogue based on a generic, multi-language client server application (MDWEB). The first version of CIAO gathers 236 metadata files that deliver information about geographical data on natural, human and regulatory parameters from local to regional levels and with various quality standards.