We have a lot of FCC from canceled cruises and are trying to optimize use of it. We were looking at taking a large family alaska or eruope cruise and wanted to get the 10% on board booking discount. My idea was to take a short, relatively cheap, cruise with just my wife and me and book 2 staterooms for the expensive cruise while on board. My understanding is that if I use FCC to book the short cruise then all of the remainder will become OBC. However, can I book this short cruise cash and then use the FCC to book the future sailing?