CoAir shows Flight 4045 to FLL has 17 seats open. 4016 to PBI has 10 open. You shouldn't have problems getting into FLL. I'm not sure how accurate it is on certain flights, but the United app will sometimes give you availability by going to Flight Status and using the Seat Map and Stby Passenger List (but you have to account for people who have not checked in and are not yet assigned a seat). But for a last minute load check, it gets you in the ballpark and will let you know if the flight is booked or not. Silver flights also show up since they have UA flight number (for your future Bahamian surfing adventures :-P). Hope your board makes it back safely.