The Shannon Estuary is a large, tidal saltwater body forming the final section of Ireland's longest river, where it meets the Atlantic Ocean. It is a significant coastal feature, approximately 102 kilometers long, stretching from Limerick city out to the open sea. For paddlers, the estuary presents a distinct environment compared to the sheltered freshwater loughs upstream. The water is influenced by strong tidal flows, and the open exposure to the Atlantic can generate significant swells and wind-driven waves, which are primary hazards. The estuary's character is one of a broad, open waterway with expansive views, bordered by the counties of Clare, Limerick, and Kerry. It is ecologically rich, designated as a Special Protection Area, and is known for its populations of wetland birds and dolphins, which are regularly observed from the water. Historical sites like Carrigafoyle Castle and Scattery Island, with its ancient monastic heritage, are notable cultural landmarks along the shores. The estuary is part of the wider Shannon Blueway network, which terminates at Killaloe in County Clare, suggesting this may serve as a transition point from river to estuary paddling. Paddlers must be prepared for variable conditions, with wind and swell being the principal safety considerations, and should plan trips carefully around tides and weather forecasts due to the exposed marine environment.