Tremadog Bay is a broad, shallow embayment on the west coast of Wales, forming part of Cardigan Bay and enclosed to the west by the Trwyn Cilan headland. The bay is bounded to the south by the extensive rocky reef of Sarn Badrig, which runs westward for 14 miles. The underwater terrain features a mix of clean sand banks, rougher ground patches, and the deeper, muddy trench known as Muddy Hollow. The bay's sheltered nature results in relatively slow-running tides, making it a forgiving environment for anglers. The presence of extensive subtidal seagrass beds contributes to its ecological richness, providing vital nursery habitat for numerous fish species. The surrounding coastline, with towns like Porthmadog and Criccieth, offers picturesque access points and a long-standing maritime heritage.