I never thought about how uncommon the tide was at Mont St Michelle. It is famous for becoming an island at high tide. I just assumed all tides along that coast were dramatic. But it seems to be exclusive to that bay.
Why are there such high differences around Britain and pretty much nowhere else? I understand why the Mediterranean sea has almost none, such a large volume just can't pass the Gibraltar, but I don't understand why there is so much water moving around Britain. Is it just water moving along and being stopped by land wihnout having much other places to flow?
As someone living in the Baltic tides have always been so weird. My local lake is at most 5 meters deep, mostly around 3. Would they just dissappear completely?
In order for the tides to rise significantly in the Baltic or Mediterranean, you'd need that much extra water to flow through the narrow opening in the straits of Gibraltar/Denmark.
The Baltic sea also probably is less affected because it's so far north, and the tides are based on the Moon's (not-quite-equatorial, but not THAT inclined) orbit.
This seems to happen anywhere sea water reaches into narrowing areas. Volume vs area.
Bay of Fundy also has large tidal differences. Hike out on Cape Split and you can watch them happen. Or dine above the Reversing Falls in St. John, NB at the right time.