Historical clue formulations

• Takes a dive, perhaps — 2022-12-13
• Visits a school, maybe — 2018-10-07
• Dives with a tank — 2018-03-02
• Explores with a tank — 2009-12-20
• Gets in over one's head? — 2001-11-01
• Breathes deeply? — 2001-03-23
• Heavy breathers? — 2001-01-20
• Takes a dive — 1997-09-12
• Goes diving — 1995-02-18