The Bristol Channel is a major saltwater inlet and arm of the Celtic Sea, stretching approximately 70 miles long and between 5 to 43 miles wide, with a coastline of 219 miles. It separates south Wales from the north coasts of Devon and Somerset in England. This channel is renowned for having the second-highest tidal range in the world, which creates powerful currents and a dramatic intertidal landscape of mud banks, sand bars, and rocky outcrops. The water depth varies significantly, from around 30 feet to a maximum of 240 feet in the central channel. The seabed composition is diverse, featuring extensive muddy and sandy substrates, particularly in the upper eastern reaches, transitioning to rougher ground and rocky coastlines along the Exmoor and North Devon shores. This combination of extreme tides, varied habitat, and rich estuarine inflows from major rivers like the Severn, Avon, and Taff supports a prolific mixed fishery.