Sandra and I waited until the last minute to decide on getting married. We did the ceremony in Galveston some 3 hours before the Conquest was to set sail with us on her. We didn't want to have to change before we boarded and thought that, maybe, Carnival would let us go past the line to VIP and get on while in our wedding regalia. NOPE!
So we had to do change after our ceremony and stand in line with our gear and not get a break to enjoy ourselves early. Live and learn.