This study seeks to examine the economic impact of companies that offer water-based activities (WBA) to their localities in Ireland. Marine based water activities generated €74.3 million in turnover to the Irish economy in 2007 of which €40 million was Gross Value Added. The sector employed 1090 individuals in Full Time Equivalents. Previously, the local economic impacts of WBA were difficult to measure due to lack of micro data and literature on the sector. This study takes previous national level research on the value of WBA further, by examining the demographics, visitation patterns and expenditures of WBA participates in the West of Ireland. This paper used a face-to-face survey to collate information on participant characteristics and their expenditures on WBA in the local economy during the summer of 2010.