Winning a "free" cruise means you should not be asked for port fees, taxes, etc. If you are asked to pay anything, it's not free, is it?
Per Tamianth:
Its ILLEGAL to ask for money to receive it - or other prizes!
Prize Offers: You Don’t Have to Pay to Play!
http://www.ftc.gov/bcp/edu/pubs/consumer/telemarketing/tel17.shtm
http://www.consumer.ftc.gov/scam-alerts