I'm having trouble even imagining an 11 m tide. When I lived near the coast, it was maybe 30 to 50 cm at most.
For reference (and because I know you like whirlpools and youtube videos), a 1.7m tide going through a constriction causes the Naruto whirlpools.
I believe (without having read anything about it) that it's because the river is a lot more "constrained" unlike the sea, so the big height difference must have to do with the morphology of the place.
Thanks for the cool video! :D