The boat ride is an entertaining and relaxing way to get a good look at what happens along the shores of the river, and you also get an impression of just how much boat traffic there is in that area. Lunch, dinner, and drinks are also served, but I would stick with a drink and take it out onto the deck.
Pic #1: Boiler room on the boat (M became suddenly eight years old when we went in)
Pic #2: The wheel!
Pic #3: An abandoned school in the lower 9th ward.