Half Moon is classified as achieving Excellent Water Quality in 2025 based on the assessment of bacteriological results for the period 2025 and 2024. Half moon received an Excellent Water Quality result in 2024. Half moon was newly identified in 2024 as a beach for monitoring, management and assessment under the requirements of the 2008 Bathing Water Quality Regulations. Annual water quality ratings are generally calculated using monitoring results over a four-year period and are assessed against stringent bacterial limits to protect bather health.

The Half Moon Bathing Water is located approximately half way along the Southside of Great South Wall. It is not a beach and access to the bathing water is via ladder or slipway from the Great South Wall. Access for pedestrians along the Great South Wall is permitted solely by foot or bicycle. Vehicle access (except for emergency vehicles) is limited at the beginning of the wall, where bicycle parking and car parking facilities are located. For additional parking, it is encouraged to use the nearby Shelley Banks car and bicycle parking facilities and refrain from parking along the roadway to prevent disturbance/damage to sand dunes. The bathing area is bounded by the Great South Wall to the North and the Irish Sea to the South thus flora and fauna have limited opportunity to grow. However, due to its position and coastal connection to Sean Moore Park and the Irishtown Nature Reserve, it is of international importance for migrating Light-bellied Brent Geese and of national importance for nine other waterfowl species. The Half Moon bathing location is located within the South Dublin Bay and River Tolka Estuary Special Protection Area (SPA), the South Dublin Bay Proposed Natural Heritage Areas and South Dublin Bay Special Area of Conservation (SAC). It is encouraged to check wind, weather and tidal forecasts before swimming. During times of adverse weather, Dublin Port Company (https://www.dublinport.ie/public-notices/) and Dublin City Council will issue a public safety notice for the temporary closure of the Great South Wall.