Prepare your passport and make sure it has a valid F1 visa stamp to go in and out of the United States. According to the Western Hemisphere Travel Initiative, "all air travelers returning to the U.S. from the Caribbean are required to present their passports at U.S. Customs." Your passport must be valid for at least six months beyond the day of re-entry to U.S.
Secure a Form I-20 travel endorsement from your university. This is usually valid for a one-year period from the date it was signed. For anyone under post-completion optional practical training, the issued travel signature is only valid for a six-month period. Additional documents may also be required for presentation, including a letter from an employer confirming that you are employed or offered employment and supporting financial documentation.
Travel in Canada, Mexico or the Caribbean with an expired F1 visa is possible through "Auto Revalidation." This may apply if the travel is for business or pleasure and the maximum stay is up to 30 days. Make sure you have a valid F1 status, an I-94 marked "Admitted F-1 until D/S" and have a recent travel signature on your I-20. These must be handled through your university's international students office or department.
During your travel from the United States to the Caribbean, check your I-94 card prior to leaving the inspection area to ensure that it is properly notated with F1, D/S. Your card and passport will be readily returned to you, so you don't need to receive a new I-94 card upon re-entry to the United States. Otherwise, if the I-94 card is removed, you must get a new one with F1 notation first upon re-entry.
Secure all your travel documents when returning from the Caribbean to the United States. Upon reaching the U.S. port of entry, show your passport and the rest of your prepared travel documents such as the Form I-20 and supporting financial documentation to the immigration inspector.