Historical clue formulations

• Shallow boat with a square stern — 2025-12-16
• Small, flat-bottomed boat — 2021-03-10
• Flat-bottomed boat — 2020-03-23
• Flat-bottomed boat — 2016-08-21
• Flat-bottomed boat — 2008-04-20
• Solo racing boat — 2005-02-17
• Boat on a lake — 2000-09-09
• Small boat — 1999-10-07