"Capt. Doug" wrote in message
...

If you arrive in the US on a major airline, you will likely be issued a
green form in lieu of a visa. Keep the green form with during your trip
around the Caribbean or you won't be allowed back in the US. Enjoy your
trip!

As Martin suggests, I think it's more difficult than that. I've heard from
UK pilots who got into trouble presuming that they would be allowed to use
the visa waiver program when, after a trip to the Bahamas or similar, they
arrived back in the US in a light aircraft. You may need a full B-2 visa.

http://www.immigration.gov/graphics/...spect/vwpp.htm

"When Must I Obtain a Visa Instead of Using the VWP?
If you intend to arrive in the United States aboard a non-signatory air
carrier, you must obtain a nonimmigrant visa prior to boarding the
aircraft."

Julian Scarfe