I am looking to book a cruise for for my wife and I and another couple who never cruised before. With that said If I book the cruise where I am in the first cabin and my wife in the second cabin it will save the other couple $600. I know that it will be possible to switch who is staying in what cabin, but can this be done in advance before the cruise, if so how or the only option is to wait until we board the ship? If we have to wait until we board the ship is it easy to switch the names for each cabin or is it better to just ask for additional cards to open each cabin? Thanks in advance!