I have heard that there are boat rides on the Tibur, although I never saw any. Looking at the picture, you can see why the Tibur is not like the Seine in Paris. The walls are high, and along much of the Lungotevere (the roads on either side of the Tibur), trees make it impossible to see anything anyway.
If you want to see the Tibur from water level, go to Tiburina, the island in the middle of the Tibur, and walk out on the flat spaces on either end of the island.
The photo was taken from a bridge over the Tibur near one end of Tiburina, looking downstream towards the Ponte Rotto (the single arch in the background). The building on the right hand side is on the island of Tiburina, on which you will find a hospital, a trattoria or two, and other assorted buildings. Once you are there, you will notice that the entire island is shaped like a boat in the river (the river passes on both sides), with a bow and stern. There are bridges from either bank that let you walk on to the island.


