I don't think Triumph is one that has had the Seaside Theatre added. If I recall Legend just received it but not Miracle when they dry-docked, someone please correct me if I'm getting the ships mixed up.
02/20/2011 Carnival Victory (San Juan - S Carib)
07/11/2010 Carnival Freedom (W Carib)
02/13/2010 Navigator of the Seas (W Carib)
05/14/2008 Carnival Spirit (Glacier Bay - Alaska)
11/12/2007 Carnival Freedom (US Inaugural - W Carib)
02/01/2007 Celebration (Bahamas)