I am leaving from Port Canaveral and returning to the same port. (Eastern Caribbean). I was told I will not need a passport just a birth certificate and other form of ID such as a drivers license. Can anyone confirm that this is true?
Read our Passport FAQ for the details. Remember that it has to be either an original or certified copy of a birth certificate issued by a government agency, not a plain copy or a notarized copy. Also note that while you don't need a passport for closed loop cruises, if for some reason you had to leave the cruise to fly home you'd have a problem. All flights to the U.S. require a passport.
Also, If you miss the ship for what ever reason, you will need a passport to fly and meet the ship.
When I was on the Legend in May, all non US Citizens - and any US Citizens who joined the ship had to go through immigration in the main lounge on the ship. There was a couple who missed the ship due to a delayed flight and had to join us in immigration.