Historical clue formulations

• Longship builders — 2025-10-25
• Vikings, e.g. — 2024-08-22
• 5-Down and cohorts — 2016-03-30
• Old salts — 2006-09-23
• 10th-century raiders — 2005-04-22
• Noted seafarers — 2001-02-04
• Vinland visitors — 1998-11-28