Traveling by air into the Bahamas from the United States requires all travelers have a valid U.S. passport, no matter the age of the traveler. Passports are books with your photo, personal information and citizenship information. This book is not required for entry into the Bahamas, as Bahamian officials only require that you prove your citizenship and identity to enter the country; however, the U.S. government will not let you re-enter the country without a passport.
If you are arriving in the Bahamas by private boat or cruise ship you can use a passport card in lieu of a passport book. A passport card is similar to a passport book as it contains the same information as your passport book. The difference between the two is that the passport card is the size of your driver's license and only permitted for use in land and sea travel between the U.S., Canada, Mexico and Caribbean Islands. Passport cards are also significantly less expensive than passport books.
Passport cards and books are both issued by the U.S. Department of State. You must apply for a passport or passport card at your local passport acceptance facility, which requires you fill out the correct application form and provide the correct forms of identification as well as two passport photos (see Resources). Passport cards and books take roughly four to six weeks for delivery from the date your application is submitted, unless you expedite the handling to two to three weeks for an additional $60.