Like paying off your cruise before the due date I dont understand the concept of prepaying gratuities. Granted its nice not to have the expense at the end of your trip but why give them money well before its earned or before you have to? Why not set aside that cash into an account and earn a couple bucks of interest? Carnival loves the idea of prepaid so they can accrue interest that should have been yours to begin with. Makes absolutely zero economical sense to me...
2008-Valor and Glory
2009-Spirit and Splendor
2010-Freedom of the Seas and Mariner of the Seas
2012-Allure of the Seas and Navigator of the Seas