First, look it up in TIMANTIC (avail. free on DL's website), the generally accepted database which will tell you based on citizenship, residence, departure, and destination what you need for what country and for how long. Print that out.
Second, armed with that information, call Disney Cruises, ask them to confirm #1 above and note your record.
Third, if you do require a visa, make sure that you start the process immediately. We are coming up on holidays and then high season for the Bahamas.
Fourth, make sure that you have, in hand, the proper documents, if any, at time of boarding.