Historical clue formulations

• Harbor bobber — 2025-12-13
• Bobber in a lake — 2025-10-21
• Object marked with the speed limit, sometimes — 2025-09-19
• Bay bobber — 2025-02-25
• Nautical marker — 2025-02-18
• Floating marker on a swim course — 2022-03-28
• Marina marker — 2021-06-08
• Hearten — 2021-04-21
• Floating marker for a sailor — 2014-04-07
• Lift — 2013-01-13
• Water mark? — 2006-08-27
• Uplift — 2006-06-16
• Hazard warning — 2003-06-17
• Channel marker — 2003-02-19
• Bay bobber — 2000-04-13
• Uplift — 1999-08-27
• Marking float — 1997-06-03
• Underwater hazard marker — 1995-06-13
• Gull's perch — 1994-08-20