Looks like Ariel's grotto opens later than the rest of the park at 10. Have you gone there right at 10 or a little earlier to get in line? Do you know when they open the line to begin to wait?
I'm not sure if there is a pre-opening queue or not, but according to thrill data the posted weight is 10 to 20 minutes at opening so I would assume the queue is minimal if there is one.