<Ul> <Li> During World War I the Irish Sea became known as "U-boat Alley", because the U-boats moved their emphasis from the Atlantic to the Irish Sea after the United States entered the war in 1917 . </Li> </Ul> <Li> During World War I the Irish Sea became known as "U-boat Alley", because the U-boats moved their emphasis from the Atlantic to the Irish Sea after the United States entered the war in 1917 . </Li> <Ul> <Li> The Port of Barrow - in - Furness, one of Britain's largest shipbuilding centres and home to the United Kingdom's only submarine - building complex, is only a minor port . </Li> </Ul> <Li> The Port of Barrow - in - Furness, one of Britain's largest shipbuilding centres and home to the United Kingdom's only submarine - building complex, is only a minor port . </Li>

Where does the irish sea start and end