Batobus on the Seine

I love the Batobus so much I've bought an annual pass, though D. would tell you I don't have to like something very much to spring for the annual option. Every time he turns around I seem to have become a "friend" of yet another museum!  The Batobus isn't the most efficient way to get around town and this isn't what it's designed for but I love it. 

It's a perfectly reasonable mode of transport for the very small number of  people who have lots of time and who are prepared to go out of their way on a very limited circular route. Despite this I love the quiet glide of the boat up and down the river and the views of the  buildings as you pass by. There are some unbelievable glass walled apartments on the left bank and I'm feeling serious real estate envy.
We're only five minutes from the Hotel du Ville stop and I don't mind waiting for the boat because there's a lovely view of the Ile St. Louis and the Ile de la Cité from the small riverside park. The annual pass is 60 euro and I've already used it a lot, I love the views looking up from the river, below you can see the very end of the Louvre and the Notre Dame at sunset.
Often I use it  one way to the Louvre or the d' Orsay if I'm tired. When I visited the Jaquemart-Andre Museum I took the boat to to the Champs Elysee and walked north from there. Last week I walked from the Musee Marmottan-Monet to the Eiffel Tower to take the boat home instead of the metro, it takes a lot more time but I enjoyed it. D. and S. opted for a more logical route home on the metro!
The Batobus  runs in a circular route from the Hotel du Ville to the Louvre, then the Champs Elysee, before  turning  beneath the Eiffel Tower to return along the left bank. On the way back it stops  at the d'Orsay, St. Germain, Notre Dame and finally the Jardin du Plantes. 
The Batobus stops behind Notre Dame  and this is the view.
In the middle of February - on the day when  I bought the pass, I took the last boat from the d'Orsay to Notre Dame around 6pm and I was the only passenger on the boat. I felt like a queen and for a moment Paris was all mine.
Around that time several stops including the Hotel du Ville were closed because of high water levels on the Seine (la crue in French), apparently this happens intermittently over the winter and early spring months. Note, when they cut back the number of stops the daily ticket price drops to 9 euro.

Recently I've noticed how many more people there are using the boats and how many more tourists there are in Paris overall. Perhaps the tourists are like the swallows, predicting the changing seasons, I suppose this means spring must be just around the corner!
Practical details: The annual pass was only available at the d'Orsay stop and you'll need to provide a passport photo.  A one day pass is 15 euro, 18 euro for two days and 21 euro for five days, there are discounts for children and students.