Possible Clues:

• Leads numerous navigators in circumnavigating ancient mariner's river
• The longest river in the British Isles
• Quiet, girl on Irish river
• Name borne by quiet anonymous Irish river
• Major Irish waterway
• Quiet woman on river
• River people of northern Burma with no name
• The first ever duty-free shop opened at ____ airport in 1947
• Longest river
• Quiet before long surrounds northern river