Historical clue formulations

• Sea connectors — 2026-07-26
• Narrow waterways — 2020-05-11
• Some shipping routes — 2014-08-31
• Narrow passageways — 2010-05-10
• Geographical connectors — 2001-02-15
• Difficulties — 1998-05-16
• In dire ___ — 1997-12-29
• Narrow waterways — 1996-10-21