Clew Bay is a large, sheltered bay on the Atlantic coast of County Mayo, dotted with over 100 islands, with local folklore claiming 365. The actual count is 141 named islands, which are partly drowned drumlins formed by glaciers. The bay sits between Croagh Patrick to the south and the Nephin Beg mountains to the north. The inner reaches of the bay are calm, protected, and ideal for beginners and families, with more exposed conditions found near the mouth. The overall character is one of island hopping among uninhabited islands, with views of the distinctive conical peak of Croagh Patrick.

Primary access points for paddlers include the town of Newport, where the Black Oak River flows into the bay, and Westport Quay on the southeastern corner. Commercial kayak and SUP operators are based at Newport and on Collanmore Island, offering guided trips, equipment rental, and high-speed rib transfers. For independent paddlers, a slipway is available at the west end of Roman Island at Westport Quay. The channel into Westport is well-marked, but vessels can only berth alongside the quay at high water, indicating a significant tidal range that must be planned around. The bay is home to seal colonies, and sightings of seals, kingfishers, and otters are common. Notable sights include the remains of old cottages on islands, Dorinish Island (once owned by John Lennon), and Clare Island, the largest island in the bay with Grace O'Malley's castle at its harbour.

The best conditions are on calm days with good light, as grey weather can make the bay appear bleak. The activity is highly weather-dependent. While no specific water temperatures are given, operators provide wetsuits, indicating generally cool water. The bay is noted for rich marine life, including seabirds and dolphins. There are no indicated restrictions specific to paddling, but the presence of cruise boat traffic from Westport Quay and the need to navigate a marked channel suggest paddlers should be aware of other vessels.