I'd presume after all these years precident has been set and you would be tresspassing on their property......as you would be on my land that I mentioned above. Mine was dry land, with nothing but a non-navigable creek, and ducks unlimited built a dam 20+ years ago and flood the land. Marsh bottom or "on" the water you are tresspassing on my property. The Scugog Marsh appears to be no different.