This is a photo I took this September of a Dutch barge liveaboard on the Seine River in Paris. The boat is moored opposeite the bottom of the Isle de Cite, the island Notre Dame cathedral is on. The bottom of the island is opposite the boat. The big building on the far shore is the Louvre.
We first saw this boat in 2001 and it has been in the same place since then. It is beautifully maintained. The city allows liveaboards to park their cars on the quay next to their boats. Whoever lives on this boat has a very expensive car based on what we saw in 2001. Didn't see a car this time, but given the condition of the boat I expect the owner is very wealthy.
You can see the starboard leeboard in its retracted position. The port leeboard is the same.
The boats moored along the Seine are moored using long standoffs, pipes that can pivot up and down at each end. Some of them incorporate big springs in one or both ends. This allows the boats to ride the sometimes huge boat and power barge wakes on the river without damage against the quay.