Clear weather, sunny day. traveling north to south... from my 9 o'clock to 11:30. flying below mountain ridge line, allowing view against backdrop of 지리산 (Jiri Mountain). fast, steady speed. relatively regular altitude. no audible noise. first appearance was vivid white color... throughout duration, sometimes appeared to be very pale gray. gurye gets regular military fly-overs during u.s./s.korea military exersises. conventional jets, very loud, very fast. this was similarly fast, but no accomanying noise. checked out youtube. saw a video of sighting in 부산 (Busan). _very_ similar appearance . . . video below.