The Marine Irish Digital Atlas (MIDA) is an Internet resource built in a web GIS environment, where people interested in coastal and marine information for Ireland can visualize and identify pertinent geospatial datasets and determine where to acquire them. The atlas, which is being constantly maintained, currently displays more than 140 data layers from over 35 coastal and marine organizations both within Ireland and abroad. It also features an "InfoPort" which is a repository of text, imagery, links to spatial data sources and additional reference material for a wide range of coastal and marine topics. The MIDA team has been active in the creation of the International Coastal Atlas Network and the Atlas was chosen as one of the nodes for the Semantic Interoperability Demonstrator. © 2011, IGI Global.