Chicago Line Cruises is a great little find if you're looking to do a boat tour of Chicago. Yesterday was a spectacular day in Chicago and Bill and I took the architectural tour with my friend Kathleen Skolnik as our guide. She's fabulous! Very knowledgeable, very accessible, and an excellent speaker.
Chicago Line Cruises is a little out of the way and tends to be overshadowed by the boats at Navy Pier and the Michigan Avenue Bridge, but I highly recommend it. Especially if you get Kathleen.
Check them out. Go to 465 N. McClurg Court and walk east on the River East Art Center promenade (that used to be the North Pier Terminal), to the ticket office. That's behind Fox and Obel on Illinois St.