So, you are IAH, the specific airport for Houston is very important. If you were at HOU I'd say 11:38 would be OK about 95% of the time. IAH is almost 70 miles from Galveston. If it all works getting off the ship, getting your transportation, getting to IAH, all the stuff required these days at an airport, then maybe it would work. If it doesn't work, will Jet Blue put you on another flight on another airline to the New York City area at no charge? I wouldn't take the chance, but since over 80% of the flights out of IAH are United, I use them all the time.