Severn

The Severn estuary opens westward into the Bristol Channel, separating the shores of southern Wales and southwestern England. Its exceptionally large tides uncover mudflats and sandbanks and drive strong currents through the narrowing waterway. The rivers Severn and Avon bring ships toward inland ports, including Bristol, while the channel provides a route out to the Atlantic. Sailors approaching these shores must account for the changing depth and force of the tide, which can transform the appearance of a harbour or a channel within hours.