Passports are required to travel if you plan to travel out of the country. If you are cruising, a passport is not required, however, highly recommended. If the cruise is a closed loop (ex. depart Miami, FL and return to Miami, FL) you can use your original birth certificate and valid government issued ID to cruise. If you plan to travel state to state, or to a U.S. territory, a passport is not required, only a valid government issued ID.