French Canal Airdraft

Some years ago, I had a few weeks on the French canals from Calais up
to Paris, then back down the Seine to Le Harve, in a small yacht - I
took the mast down of course!

I'm now thinking about having a bit longer there, and putting a
motorboat somewhere handy. Does anyone have an overall airdraft figure
which would get you through the whole system? I was told that the Canal
du Midi had lower airdraft bridges, and would also like to know if this
is true!

Thanks for reading this - and thanks in advance if you can help!