What would a trip to Hannibal, Missouri be without a riverboat cruise?
Oh, wait, that was a rhetorical question not a dumb joke. We took an hour-long cruise on the riverboat Mark Twain. First up to the Mark Twain Bridge, then down along the middle of the river to approximately where the Mark Twain cave (yes, everything in Hannibal is named after Twain) is located, finally returning up along the eastern shore.
There was entertainment and informative tour-guiding along the way but mostly I remember it being oppressively humid and 98 degrees outside.