Actually there is one other that I know of.... its been around for quite a while....
Ever heard of the living seas at disneyworld? They offer a program that lets you dive in there fora half or full day (dont know the exact details)... Its not a widely advertised program but it was featured on a discovery channel exclusive on the secret world of disney.... any certified diver can do it....
http://disneyworld.disney.go.com/wdw/parks/attractionDetail?id=TheLivingSeasPavilionAttractionPage
Its called DiveQuest... I dont know how much it costs but it would be an amazing experience im sure... plus their aquarium I believe is much bigger than the one in Chicago is supposed to be...