Portnablagh is classified as achieving Good Water Quality in 2025 based on the assessment of bacteriological results for the period 2022 to 2025. Portnablagh achieved a Good Water Quality rating for the four consecutive years 2022 to 2025. 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.

Portnablagh beach consists of a small sandy beach; confined by Portnablagh pier to the North and a small headland to the South. Portnablagh beach supports a variety of wildlife including birds and shellfish. The site is part of a Special Protection Area (SPA) under the E.U. Birds Directive, of special conservation interest. This is because of rare bird species present. Activities at Portnablagh beach include swimming, kayaking, boating, windsurfing, sailing, surfing, power boating, jet skiing, diving and other land based activities on the beach. The beach is located beside the small working pier and slipway. There is a very deep gradient off Portnablagh Beach with the water depth reaching 1m approx. 10m from the water line and continuing out at a deep slope.