Found an awesome hidden Mickey a couple of days ago at the Boardwalk Inn
Location: Boardwalk Inn, Luna Park Pool, Keister Coaster Water Slide.
When riding the slide, before you hit the first turn, look down on the slide and there is a classic hidden mickey on the slide. It looks like a stain on the slide, but is in the perfect shape of a hidden mickey.
You can actually see part of the mickey before getting on the slide. On the platform before you get on, move all the way to the left and look at the slide. Look to the floor of the slide before the first turn and you can see a visible spot on the slide. That spot is half of the hidden mickey.
The best part about this Mickey, riding the slide to get to the bottom!