I think it is best to visit Voies navigables de France
(voies navigables de France) where you can read from the authority about everything you must know to navigate the french waterways
. On this site you can also buy the vignette what is compulsory to navigate. The site is in severalt languages, also in English
is not where you plan but I sailed up the river Saone this summer with my grand children
(10 and 12 years old). They liked it and had much fun as I had.