Historical clue formulations

• Vertical, to a sailor — 2018-04-15
• Vertically, to a sailor — 2016-02-07
• Vertical, at sea — 2012-04-28
• Vertically, to a sailor — 2010-08-17
• More or less vertical, at sea — 2008-03-19
• Vertical, at sea — 2007-02-13
• More or less vertical — 1997-08-08
• Vertically, in nautical talk — 1996-04-22
• Approximately vertical, at sea — 1995-05-30
• Vertical — 1994-11-21
• More or less vertical, to a sailor — 1994-05-01