We used our FCC to book two cruises, so we won't have the "leftover" for onboard credit for the first. Is it possible to use some of the FCC to put money into our onboard account for the first cruise and not have quite as much to apply for the second cruise? We did pre-pay gratuities but I was wondering if it's possible to put some "generic" funds into the onboard account that could be used for excursions, drinks, shopping, etc.