go to Big Thunder, go into that little entrance. You reach the middle balcony. Go back in. Go down the waterfall. Go to your right, exit. End up somewhere down there.. go back in the exit you came from. You'll be at the top i think.
Oh, I don't have dive magic. Wish they would've mentioned that it was needed. I wouldn't have spent all that time trying to get to that darn horseshoe!
Not one of my favorite quests, very hard to find the clover, and very difficult to get through the mine. But nice that Hula had a quest and a nice prize.