From the article ASD linked to:
"Lou Sandoval, commodore of the Chicago Yacht Club and national director of business development for Nautic-On, said the marina would be convenient for boaters. “I think the location is unique — it’s in the epicenter of our city right next to Monroe Harbor,” he said. “The only question I would have is whether it can attract enough boaters, given that there’s been a surplus of slips at a lot of harbors in the city.”
That's the first I've heard that Chicago has empty slips.