Exploring Chicago on a kayak is one of the best sightseeing options in this city. There are many guided tours in historical parts of downtown. You can also choose a romantic night tour or watch fireworks from a kayak over the Michigan Lake.
If you don't want a guided tour you can just rent a kayak and go through the downtown by yourself looking at the city from a practically different angle! However, keep in mind all the safety rules that kayaking companies set out and always check out the weather before getting ready to go!