At Christmas time, I wanted to change our cruise from Radiance to the new Ovation of the Seas. When I called Royal Caribbean, I was told they do not transfer deposits, so I had to cancel Radiance (and wait approx. 3 weeks for the money I had paid to come back to my credit card), then I had to pay the new deposit to secure our booking on Ovation of the Seas.....
It is also worth mentioning, that I kept an eye on my refunded deposit as it came back in bits. Once I added these bits up, I had been short changed $200 odd AUD, so worth checking your bank account to ensure you get all of your deposit back....