If you head over at rope drop, the wait would be walk on to 20 minutes depending on how fast you get over there. If you go straight, maybe a few minutes wait. If you are thinking about other attractions as well, the later in the EMH hour, the longer the line. I would guess no more than 30-40 minutes max if near park opening time. It does depend on when you are going. The busier the season, the more people that will be in the park for EMH. Good luck.