We have always boarded between 11:30 and 1:30 and the worse was for MSC as the agens were new with a new system.
My only suggestion if you want to board late is to be sure just how late you can board and not be later than the lice tells you. I understand that people are beign turned away because of being as little as 5 minutes late, have read about this on other forums. It seems for most lines you have to be on board now 90 minutes prior to sailing. I know for our cruise next April MSC has set 3 hours prior or not allowed to board. I don't know if there is a new regulation that has been set or what.
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013, Carnival Legend Nov 2013, MSC DIVINA Jan 2014