As I understand it, the government taxes and fees that are added, generally cover:
port taxes which cover the disembarkation for each port, similar to a gateway tax that you pay for airline tix. As far as I know these are the "taxes" that we pay.
A good resources to check with would be the Attorney General of Florida. I had questions regarding fees on my cruise, etc., and I was directed to their office who gave me a detailed accounting.