I need to fly from Busan to Jeju tonight but the airlines' websites say the flights are full. Is there any point in turning up at the airport anyway? Or am I doomed?

Which airline? Did you try all 17 of them? Jeju Air, Asiana, Korean eg? Or the express boat from Mokpo on the west coast which only takes 3 hours? (the slow boat takes 5 hours) The direct boat from Busan takes around 11 to 13 hours, so catching a bus from Busan to Mokpo makes sense if all Busan boat seats are sold out. There are a couple other boats departing from the south coast of Korea also: Yeosu, & one other I forget. Wando / Naktong ?
http://wikitravel.org/en/Jeju#Get_in
I'd also ask the airlines if it's possible to waitlist, & how many are in the queue ahead of you? Last February Korean travel agents told me it was impossible to book a seat on short notice from Korea to Japan & back. But I did it. Seoul > Tokyo > Nagoya > Seoul. Made it clear I was very flexible with entry & exit cities. Didn't HAVE to be Tokyo Narita, Hakata, Nagasaki, or Osaka eg. So check what airlines have flights to Jeju, how many airports they're are, (could be just the one at Jeju City?) & what guesthouses & motels are still available? Boats seem to depart in the morning from Mokpo. 9 am from memory.
