Bay of Biscay Shows a Tanker How It Rolls in Stormy Weather Video of a Tanker in a Storm with Huge Waves in the Bay of Biscay. The Bay of Biscay is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and the northern coast of Spain west to Cape Ortegal. It covers an area of 223,000 sq.km The water volume is 389,000 cubic km and the average depth is 1,744m and maximum depth is 4,735m. Parts o