The EUNIS habitat classification is a comprehensive pan-European system to facilitate the harmonised description and collection of data across Europe through the use of criteria for habitat identification. It is hierarchical and covers all types of habitat types from natural to artificial, from terrestrial to freshwater and marine. This data collection activity covers the EUNIS habitat classification of seabed habitat types in marine waters near Belmullet Co. Mayo along the north-west coast of Ireland. The data has been collected during the Irish National Seabed Survey (INSS) and INFOMAR seabed mapping programmes between 1999 and 2005. Data gathered via multibeam echosounder and seabed sampling data acquired during surveys were the primary sources of data used in the generation of this habitat map. The original sediment classes assigned to the data were translated to the harmonised European EUNIS habitat classification system as part of the MESH Atlantic project. Data collection and habitat map produced by the Advanced Mapping Services team within the Marine Institute. Data coverage 100% for the seabed surveyed area.