Did you already contact Navy Pier?
I'm sorry, but I am not sure!! We had ours in the Crystal Garden and didn't need a permit becuase we rented the space. I would contact them and see if they can point you in the right direction!
Looks like there is at least some contact info on their website:
44. How can I coordinate a wedding, private party, corporate meeting, tradeshow or event at Navy Pier?
Navy Pier has event space to meet any size group or occasion. Plan your next event at Chicago Landmark Navy Pier. Please click here to plan an event and for complete information about rental rates, amenities, and menus that can be obtained from the Special Events department. You may contact the Special Events department directly at (312) 595-5300 or via e-mail at email@example.com.
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