Historical clue formulations

• Reefer and clipper — 2023-12-21
• Places for cabins — 2022-08-20
• They can be used as icebreakers — 2019-11-07
• Where many cabins are found — 2019-03-14
• Missouri and Arizona — 2016-09-24
• 23-Down travelers — 2016-01-08
• Sends — 2015-07-28
• Armada units — 2012-12-25
• Things traveling on sound waves? — 2011-09-09
• Fleet members — 2011-01-25
• Sends by UPS, say — 2010-07-21
• Sends — 2008-08-28
• Freighters, e.g. — 2007-06-25
• Armada parts — 2005-09-05
• Harbor sights — 2004-06-07
• Sends — 2004-04-14
• Sends — 2002-10-27
• Places for cabins — 2002-05-12
• They're rigged — 1999-08-21
• Harbor sights — 1999-08-17
• Whalers and such — 1996-09-23
• Sends — 1996-05-26
• Armada members — 1994-04-10