If you travel to a Mexican port, then yes. Otherwise I don't think so.
Yes
It depends on your nationality and if you intend going ashore.
Yes, any out of country travel now requires a passport
If you are a US citizen, and you are sailing to and from a US port, you will never need a passport for a cruise. They have made a permanent exception to the rule for cruisers who fit this description.
not for the bahammas have a drivers licencse AND a Birth certificate.
Yes, when you travel to different countries you need your passport in hand.
US citizens sailing to and from a US port will not need a passport for a cruise. You will only need a driver's license or photo ID and a state-issued copy of your birth certificate.
If the cruise departs and ends at the same U.S. port, no passport is required; however they need a proof of citizenship, such as the birth certificate, certificate of naturalization or passport card; if the children are 16 or older, they also need a photo ID.
If it involves going to another country, yes. And if your cruise lands somewhere other than Canada, Mexico, the Caribbean, or Bermuda, you'll need a passport book, not just the passport card. Source: http://travel.state.gov/passport/ppt_card/ppt_card_3926.html
Yes, new Homeland Security rules require you to carry a passport whenever leaving the USA.
If you're a US citizen and planning to cruise to the Bahamas before summer 2008, you do not need a passport. You can also cruise to the Caribbean (except Barbados), Mexico and Canada (for most Alaskan cruises) without a passport. The Department of Homeland security should announce the new date for passport requirements later this spring.
Basically yes, to get on AND off the cruise ship you need a passport.