Go to the Triumph roll call for May 25th...
http://boards.cruisecritic.com/showthread.php?t=835586&page=4
http://www.carnivalconnections.com/cruisetalk/forums/t/57488.aspx?PageIndex=3
Plenty of info I have posted...
Short answer - ship leaves at 10pm earliest you can get into port - 4pm... may be 5:30-6ish before boarding... by Carnival it's 7pm til 8:30pm.