Verified answer

You will not be allowed to board an airplane leaving the U.S. without a passport. If you are going on a cruise to Jamaica and the cruise begins and ends in the same U.S. port, you do not need a passport. You can use a photo I.D. and your birth certificate to go on a closed loop cruise in the Caribbean.

you definitely need a passport since you are the United States

Yes you will as you are leaving the country.