This is incorrect. I just did this. I booked a March 2012 Wonder cruise through costco and got >300 gift card from Costco. While onboard the Wonder I booked again for the Magic spring break 2013 cruise out of Galveston. You tell the onboard person who books your cruise to list Costco as the travel agent. I then called up Costco when I got home and they were able to successfully move my reservation over since it was already listed as having them as the agent. I am still going to receive my >500 dollar gift card. Now with that said you might want to call Costco ahead of time and ask them what name/address the onboard agent should use for your booking. He asked me when booking and because I didn't know he used the agent's name and address that was on my booking for the cruise I was on and there were no problems. If you didn't book the cruise you are on through Costco then you might have issues when they don't know who to list on the booking. Another note based on someone else's comment above about the gift card. All Costco cash cards are exchangeable for cash. Go into the warehouse and go to the customer service counter and tell them that you would like cash for your cash cards. They will have to go to a register to get you cash but they will do it. I got our gift cards the week we returned home and I went down and exchanged them for cash so I could buy my wife a new iPad. Since Costco doesn't sell them I took the money to the Apple store and bought one there.