Welcome to CF
Do you have French residency? since Brexit it has all got rather more complicated. Worth having a good read a search on here about Brexit. This is for you to live in France
and a great goal btw
Then there is the boat. That's a separate issue and has different rules to people. If its a UK boat, well VAT and import
duty will now be due if you take it to France. Suggest then you stick to buying a boat
in the EU or risk a 20% VAT bill. Don't bring it back to the UK or you may get another 20% VAT bill.
Again worth a read on CF as it has been discussed regularly of late.
Do check the length, depth
and air draft
(under bridges) of any vessel you are thinking of buying
against the canals you want to explore. The some of the more pretty canals are quite shallow and have a low air draft