In Canada, a very old arrangement dating from the creation of the country, says that navigable water is a federal matter. Whether it’s on the side of the ocean, a big lake, or a river, the water and anything below high tide is Crown “land”, and public. There are obviously exceptions and access by land can be controlled but not by water. At least not the beach itself.

It leads to weird situations, like a provincial park that can’t stop boaters from using remote parts of “their” beach. Or another where boats band together between some islands, and party and jetboat among kayaks and SUP.

But this also prevents owners of big houses around lakes to claim a part of that lake, or the foreshore.

We don’t have the right to roam in general here, with some exceptions for Crown lands, and it happens that bodies of water and rivers is Crown land.

Anyway, that’s how I understand this.