Old thread but worth an update. There is now an ex-patriot focused, English
language sailing club in Busan. They'd be a good group to contact for more info.
Busan Expat Sailing Club
I spent a couple of years living in South Korea
and, in my time exploring Busan markets, I didn't see any rocket launchers. Things have been improving at a steady and increasing rate since the war.
I am not surprised to see interest in sailing beginnign to form in South Korea. They are excited about all manner of pursuits and acheivements. The country changed before my eyes in 2006-2008. I'd expect to see sailing grow in South Korea in the future.
Also not surprised to see the comment that the South Koreans are very welcoming. They are some of the friendliest, nicest people on earth. They are (justly) proud of their country and love to show it off. Also, the food
is (in my opinion) the best anywhere.
Best wishes to all who sail South Korea.