This paper presents the results of a weather window analysis of wave data from the west coast of Ireland in order to quantify the levels of access to marine renewables for operation and maintenance activities. Operating and maintaining marine renewables offshore requires suitable weather windows when devices can be accessed. It is important to quantify what the levels of access are off the Irish west coast, given its high wind and wave resource. Wave data from two wave buoys are analysed to quantify the levels of access that exist off the west coast. The general wave regimes at both sites are quantified. The levels of access at various operations and maintenance (O/M) access limits are presented together with waiting periods between windows. The levels of access observed off the west coast are then compared to levels of access observed at other marine renewable locations. The results indicate that the levels of access off the west coast are far below those observed at other marine renewable locations. The implications of these low levels of access suggest that maintaining wave energy converters, off the west coast, may not be feasible and devices will need to be brought ashore for O/M activities. (C) 2012 Elsevier Ltd. All rights reserved.