Historical clue formulations

• Coat, as with flour — 2024-10-09
• Clear, as a channel — 2016-01-31
• Deepen — 2007-01-14
• Bring (up) — 2006-10-13
• Change channels? — 2003-07-20
• Excavating machine — 2001-07-02
• Super scooper — 2000-08-26
• Harbor deepener — 1998-08-20
• Comb — 1995-08-26