The @links directive adds links to a page as though they were children of that page. By default the page for a directory (source file if present) has as children any sub-directories or other .md pages in that directory.

So for example the Cruises page has:

  2007/Norway		2007 Norway
  2009/eastern_med		2009 Eastern Med
  2011/black_watch		2011 Baltics
  2012/azores_cruise		2012 Azores
  2013/rhine_cruise		2013 Rhine
  2014/Azura		2014 Western Med
  2015/Eclipse		2015 Norway and Eclipse
  2016/Arcadia		2016 Western Med
  2017/Baltics		2017 Baltics
  2018/Columbus		2018 British Isles
  2019/Iceland		2019 Iceland

The format for the link is a page reference followed by one or more tabs then a link title. The processing of the source files tries to be fairly smart about references to other pages (this applies to links in @markdown sections too). So providing the reference is unambiguous it should work.