Maritime Museum La Rochelle
In La Rochelle there is a super nice maritime museum : Musée Maritime de La Rochelle. From very cute sailing boats to ships that can go directly to the ocean. Very worthwhile if you are interested in that theme.
The nice thing about this museum (mmmhhh museum sounds dull and this one is definitely not dull…) is that it is VERY spacious and in addition to the various halls, buildings explaining the smaller details of shipping / pleasure sailing, there are also complete seagoing vessels that you can visit.
More interested in pleasure boating? No problem either, rows and rows, all explanations included, all complete and a team of beautiful, very enthusiastic employees who can explain everything to you.
Only drawback: it is HUGE. So take at least a day for a visit if this is your kind of thing, you certainly need that time. For more info see: https://museemaritime.larochelle.fr/