Foreigners on US-Cuba direct flights
 

Both southwest and delta website indicate that US citizenship is needed for taking their US-Cuba direct flights. AA doesn't require on the webpage, though.

https://www.southwest.com/html/promo...vice-cuba.html
The documentation you need
A Passport - Every traveler must have a U.S. passport that’s valid at least six months after the return date.

http://www.delta.com/content/www/en_...ing-there.html
IMPORTANT DOCUMENTS
Traveling to Cuba requires a valid U.S. Passport and a Visa.

But my parents who hold Korean citizenship just finished their sweet 3-day trip to Havana last week, through Southwest. They had to declare one of those 12 general license categories which were asked only at the check-in and visa purchase. No specific document was needed to prove the category but of course, one must prepare the worst case. Anyway, there's no US citizenship requirement for taking direct flights. But prepare everything printed (ESTA and all visa documents to enter US) because Southwest check-in agents may not fully understand all visa rules. And internet is limited there.


Below are specifics to Southwest:

Upon Cuban immigration, they were asked to provide health insurance for which they simply showed Southwest boarding pass. In fact, WN doesn't collect boarding pass for Cuba flights because that is a proof of medical insurance.

If the aircraft parks far from the terminal, Southwest does chaotic bus boarding. Then they cut "up to C15" something like that. Whoever standing close to the bus doors get on board first. If the aircraft parks closer to the terminal, passengers simply walk to get board.

Cuba check-in at FLL is at the 1st floor, next to baggage carousel 6 (the one closest to TSA security). Those with bags need to go general check-in at 3rd floor after processing all at the 1st floor.

First of all, this is not specific to Southwest, but all airlines flying direct from US to Cuba.

Secondly, while Aduana is aware of this, it is not clear that clinics and hospitals in Cuba are aware of this policy, in case you ever actually need medical care. There is a letter floating around on one of the Cuba forums that explains to clinic staff that the boarding pass serves as proof of insurance. Worth finding, printing and carrying IMO.

Good idea to print that document, too. Some airlines charge separately for the medical insurance (Spirit, $25). Not sure NK passengers also use boarding pass as a proof. In any case, mobile BP isn't a good idea, and WN in general collects BP which they are not doing for Cuba flights.